Lens device, imaging apparatus, imaging system, lens control system and computer readable storage medium

ABSTRACT

An object of the present invention is to suitably perform a zooming control operation in the case that a zoom ring is provided at a lens-side portion and zoom switches are provided at a camera-body-side portion of a lens-interchangeable video camera. To achieve this object, in the case that no zoom lens stop request is provided from the camera-body-side portion, it is judged from information sent from the camera-body-side portion which of a tele direction and a wide direction the moving direction of the zoom lens group is. Moreover, when the zoom angle is not placed at a tele end or at a wide end, lenses are driven by calculating data for driving the lenses. Thereafter, tele information is set or cleared according to whether the zoom lens group is placed at the tele end, Subsequently, zoom-ring operating information is detected. The detected zoom-ring operating information is sent to the camera-body-side portion. Then, the zoom lens group is controlled by generating zooming control information at the camera-body-side portion according to the zoom-ring operating information and zoom-switch operating information.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a lens device having a zoomlens, an imaging device equipped with this lens device and adapted toperform electronic zooming, an imaging system, an lens control systemand a computer readable storage medium.

[0003] 2. Description of the Related Art

[0004]FIG. 4 is a block diagram showing the configuration of aconventional lens-interchangeable video camera. In this figure,reference numeral 100 designates an interchangeable lens unit; and 200 acamera body unit to which the interchangeable lens unit is detachablyattached. In the interchangeable lens unit 100, reference numeral 101denotes a fixed front lens group; 102 a variator or zoom lens group forzooming or changing a magnification; 103 a fixed lens group; 104 acompensator or focusing lens group for performing both functions ofcompensating and focusing. These lens groups 101 to 104 constitute alens system of inner focusing type.

[0005] Reference numeral 106 designates a stepping motor for moving thevariator lens group 102; 108 a rotation shaft that is connected to agear 107 through the stepping motor 106 and has a screw; 109 a rack thatis movably mounted on the rotation shaft 108 and provided with thevariator lens group 102. Reference numeral 105 denotes a driver fordriving the stepping motor 106; and 110 a zoom encoder for detecting theposition of the variator lens group 102.

[0006] Reference numeral 112 designates a stepping motor for moving thecompensator lens group 104; 113 a rotation shaft that is directlyconnected to a stepping motor 112 and has a screw; 109 a rack that ismovably mounted on the rotation shaft 113 and provided with thecompensator lens group 104. Reference numeral 111 denotes a driver fordriving the stepping motor 112. Reference numeral 115 designates amicrocomputer (hereunder sometimes referred to as a lens microcomputer)that communicates with a microcomputer 208 of the camera body unit 200and controls each of the drivers 105 and 111 and receives positiondetection information from the zoom encoder 110.

[0007] Further, in the camera body unit 200, reference numeral 201denotes an imager such as CCD; 202 CDS/AGC circuit for performing acorrelated double sampling operation and an automatic gain controloperation; 203 A/D converter; 204 a signal processing circuit; 205 anenlargement processing circuit for performing electronic zooming; 206 asignal processing circuit; 207 D/A converter; 208 a microcomputer(hereunder sometimes referred to as a camera microcomputer) forcontrolling the entire video camera and for communicating with the lensmicrocomputer 115; 210 and 211 zoom switches for moving the variatorlens group in a tele or telephoto direction and a wide or wide-angledirection, respectively; 212 and 213 focus switches for moving a focusposition to an infinite focus position and to a shortest focus position,respectively; and 209 a group of these switches.

[0008] Next, an operation of this video camera will be describedhereinbelow. When the interchangeable lens unit 100 is attached to thecamera body unit 200, electric power is supplied from the camera bodyunit 200 to the interchangeable leas unit 100. Then, an image is formedon the imager 201 from light that comes from an object through the lensgroups 101 to 104. Video signals obtained by photoelectric conversionperformed in the imager 201 are processed by the CDS/AGC circuit 202.Subsequently, the video signals are converted by the A/D converter 203into digital video signals which are then sent to the signal processingcircuit 204. After the signal processing circuit 204 gamma-corrects thedigital video signals, the enlargement processing circuit 205 performsenlargement processing (to be described later) on the gamma-correctedvideo signals. Further, the signal processing circuit 206 performsbalanced modulation on color signals. The processed signals areconverted by the D/A converter 207 into digital analog video signalswhich are then sent to VTR (not shown).

[0009] Next, operations of the lens microcomputer 115 and zooming andfocusing operations will be described hereinbelow. When the zooming orfocusing operation is designated, the lens microcomputer 115 determinesthe rotation speed and direction of each of the motors 106 and 112 byexecuting programs. Further, the lens microcomputer 115 outputs controlsignals representing the determined rotation speed and direction, andcontrols the stepping motors 106 and 112 through the drivers 105 and111, respectively. Incidentally, regarding the zooming operation, thelens microcomputer 115 determines the rotation direction of the motor106 according to the states of the switches 210 and 211, which arerepresented by signals outputted from the camera microcomputer 208,respectively. Regarding the focusing operation, in the case of adjustingfocus by a manual operation, the rotation direction of the motor 112 isdetermined according to the states of the switches 212 and 213, whichare represented by signals sent from the camera microcomputer 208. Onthe other hand, in the case of adjusting focus by an autofocusing (AF)operation, the rotation direction of the motor 112 is determined byexecuting AF processing routine in the lens microcomputer 115.

[0010] Each of the motors 106 and 112 rotate by being controlledaccording to the aforementioned control signals. Thus, the rotationshaft 108 rotates through the gear 107. Moreover, the rotation shaft 113rotates. Each of the racks 109 and 114 moves back and forth togetherwith a corresponding one of the lens groups 102 and 104. Consequently,predetermined zoomed and focused conditions of the video camera areobtained.

[0011] Next, enlargement processing (namely, electronic zooming) to beperformed on an image in the enlargement processing circuit 205 byutilizing linear interpolation will be described hereinbelow.Enlargement processing is performed by operating the zoom switches 210and 211 by a cameraman. When an original image shown in the left-sidepart of FIG. 5A is expanded into an enlarged image shown in theright-side part thereof, scan lines representing the original image areas illustrated in the left-side part of FIG. 5B, and scan linesrepresenting the enlarged image are as illustrated in the right-sidepart thereof. In this case, the scan lines, which represent the enlargedimage and are respectively indicated by dashed lines in the right-sidepart of FIG. 5B, are newly formed from the scan lines A to Frepresenting the original image shown in the left-side part thereof.Thus, each of the scan lines respectively indicated by dashed lines isobtained by multiplying data representing corresponding ones of scanlines, which are respectively indicated by solid lines in the right-sidepart of FIG. 5B, by weight factors (or correction coefficients)corresponding to the distances thereof and adding up resultant data. Theoriginal image can be enlarged at an arbitrary enlargement magnificationby performing such linear interpolation processing in the vertical andhorizontal directions.

[0012]FIG. 6 shows the configuration of the enlargement processingcircuit 205. For simplicity of description, this figure illustrates onlythe vertical enlargement processing. As shown in FIG. 6, input videosignals 300 are stored in a memory circuit 301 under the control of amemory control signal generating circuit 302. Microcomputer interfacecircuit 304 receives an enlargement magnification and enlargementinformation from the camera microcomputer 208. Based on this, anenlarged magnification determining circuit 303 outputs the enlargementmagnification to the memory control signal generating circuit 302 and aninterpolation coefficient generating circuit 308. The memory controlsignal generating circuit 302 reads signals, which respectivelyrepresent an nth line and an (n−1)th line delayed by 1 H (namely, onehorizontal scanning interval) from the nth line, from the memory circuit301. The interpolation coefficient generating circuit 308 generatesinterpolation coefficients corresponding to the enlargementmagnification and gives the generated interpolation coefficients tomultipliers 305 and 306. These multipliers multiply the signals, whichrespectively represent an nth line and an (n−1)th line, by theinterpolation coefficients. Outputs of these multipliers are added up inan adder 307. Resultant signal is outputted therefrom as an output videosignal 310.

[0013] Next, processing to be performed in the camera microcomputer 208will be described with reference to a flowchart of FIG. 7. In step 401,the processing is started. Then, predetermined initialization isperformed in step 401. Subsequently, in step 403, the cameramicrocomputer 208 waits for a vertical synchronization signal Vd. Whenthe vertical synchronization signal Vd is inputted to the cameramicrocomputer 208, control proceeds to step 404 whereupon the cameramicrocomputer 208 makes predetermined communication with the lensmicrocomputer 115. Thereafter, the camera microcomputer 208 performs AFoperation and an automatic exposure (AE) operation in step 405. Then,the camera microcomputer 208 performs electronic and optical zooming instep 406. Subsequently, control returns to step 403.

[0014]FIG. 8 is a flowchart illustrating the operation performed in theaforementioned step 404 in more detail. As illustrated in FIG. 8, theoperation is started in step 501. Then, the camera microcomputer 208sends a communication request signal to the lens microcomputer 115 instep 502. Subsequently, control advances to step 503 whereupon thecamera microcomputer 208 checks whether a communication enabling signalcomes thereto from the lens microcomputer 115. If so, control proceedsto step 505. If not, control advances to step 504 whereupon the cameramicrocomputer 208 waits for a communication enabling signal for apredetermined time. If no communication enabling signal comes theretowithin the predetermined time, the camera microcomputer 208 gives upcommunicating with the lens microcomputer 115. Then, the cameramicrocomputer 208 finishes the communicating operation in step 506.

[0015] In the case that a communication enabling signals comes theretowithin the predetermined time, bidirectional communication between thecamera microcomputer 208 and the lens microcomputer 115 is performed instep 505. At that time, data sent from the camera microcomputer 208 tothe lens microcomputer 115 includes information on the halt or movingdirection of the zoom lens group, which is obtained as a result of theoperation performed in the aforementioned step 406. Further, data sentto the camera microcomputer 208 from the lens microcomputer 115 includesinformation on the inhibition/permission of electronic zooming.Subsequently, the camera microcomputer 208 terminates the communicatingoperation in step 506. Then, in step 507, control returns to theaforementioned step 406.

[0016] Next, the step 406 will be described in detail with reference toa flowchart of FIG. 9. As shown in FIG. 9, an operation is started instep 601. Then, in step 602, the camera microcomputer 208 checks whetherthe camera is performing zooming. When both the zoom switches 210 and211 are pushed, or when neither of the zoom switches 210 and 211 ispushed, control proceeds to step 607. When only one of the zoom switches210 and 211 is pushed, control proceeds to step 603 whereupon it ischecked which of the zoom switches 210 and 211 is pushed. If the “TELE”switch 210 is pushed, control advances to step 604. If the “WIDE” switch211 is pushed, control proceeds to step 603.

[0017] In step 604, the camera microcomputer 208 checks whetherelectronic zooming permission information comes thereto from the lensmicrocomputer 115. If the camera microcomputer 208 is permitted toperform electronic zooming, control advances to step 605. If not,control proceeds to step 610. In step 605, the camera microcomputer 208checks whether the zoom lens group 102 is placed at a tele end. If so,control advances to step 607. Otherwise, control proceeds to step 606whereupon an electronic zooming operation is performed by increasing ordecreasing the aforementioned interpolation coefficients according towhich of the switches 210 and 211, and whereupon the cameramicrocomputer 208 controls the enlargement processing circuit 205according to a result of the zooming operation. Upon completion of thiscontrol operation, the camera microcomputer 208 sends a zoom lens stoprequest signal to the lens microcomputer 115 in step 607. Further, instep 610, the camera microcomputer 208 sends the lens microcomputer 115a request to move the zoom lens group to the tele side.

[0018] On the other hand, in step 608, the camera microcomputer 208checks whether the camera is now performing electronic zooming. If so,control proceeds to step 606. Otherwise, control advances to step 609whereupon the camera microcomputer 208 sends the lens microcomputer 115a request to move the zoom lens group to a wide side. Upon completion ofthe operation to be performed in one of the aforementioned steps 607,609 and 610, control returns to a main routine in step 611.

[0019]FIG. 10 is a flowchart illustrating processing concerning azooming operation, which is a part of the entire processing to beperformed by the lens microcomputer 115. As illustrated in FIG. 10, theprocessing is started in step 701. Then, in step 702, the lensmicrocomputer 115 checks whether the aforementioned zoom lens stoprequest signal comes thereto from the camera microcomputer 208. If so,namely, if the zoom lens group should be stopped, control proceeds tostep 708. Otherwise, control advances to step 703 whereupon the lensmicrocomputer 115 checks according to the information sent by the cameramicrocomputer 208 which of the tele direction and the wide direction themoving direction of the zoom lens group is. If the moving direction ofthe zoom lens group is the tele direction, control proceeds to step 704.If the wide direction, control advances to step 705.

[0020] In step 704, the lens microcomputer 115 checks whether the zoomlens group is positioned at the tele end. If so, control proceeds tostep 708. Otherwise, control advances to step 706. Further, in step 705,the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step 708.Otherwise, control advances to step 706. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step 706. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in step 707.Furthermore, in step 708, the zoom lens group is stopped.

[0021] Upon completion of the operation performed in step 707 or 708,the lens microcomputer 115 checks in step 709 whether the zoom lensgroup is placed at the tele end. If so, control proceeds to step 710.Otherwise, control advances to step 711. In step 710, the lensmicrocomputer 115 sends the camera microcomputer 208 an electroniczooming enabling signal. Further, in step 711, the lens microcomputer115 sends the camera microcomputer 208 an electronic zooming inhibitingsignal. Upon completion of the operation performed in step 710 or 711,control returns to the main routine in step 712.

[0022] As described above, in the case that the zoom switches 210 and211 are provided only in the camera body unit 200, optical zooming andelectronic zooming are realized under the control of the cameramicrocomputer 208. However, in the case that a zoom ring 116 to be usedfor manually performing a zooming operation is provided in theinterchangeable lens unit 100 as illustrated in FIG. 3, the conventionalvideo camera has the problem that it is difficult to achieve suitableand smooth control of optical zooming and electronic zooming.

SUMMARY OF THE INVENTION

[0023] Accordingly, an object of the present invention is to solve theaforesaid problem, thereby achieving suitable control of zoomingoperations in the case that zooming operation means are provided at bothcamera-body-side and lens-side portions, respectively.

[0024] Further, another object of the present invention is to smoothlyswitch between an optical zooming function and an electronic zoomingfunction.

[0025] Moreover, still another object of the present invention is toenable an electronic zooming function independent of whether a zoomingmechanism is provided in a lens-side portion.

[0026] To solve the aforementioned problem and to achieve the foregoingobjects, according to an aspect of the present invention, there isprovided a lens device which comprises variator lens means forperforming a zooming operation, zoom operating means for operating theaforesaid variator lens means, information output means for outputtingoperation information sent from the aforesaid zoom operating means andfor outputting zooming position information of the aforesaid variatorlens means, information input means for receiving control information,which is used for controlling the aforesaid variator lens means, from anexternal device, and variator control means for controlling a zoomingoperation of the aforesaid variator lens means according to the inputtedcontrol information.

[0027] Further, according to another aspect of the present invention,there is provided an imaging apparatus which comprises imaging means forimaging an object and for outputting an image signal, information inputmeans for receiving external zoom operating information and zoomposition information to be supplied to external variator lens means,zoom operating means for receiving internal zoom operating informationto be supplied to the aforesaid external variator lens means andinformation output means for generating and outputting optical zoomingcontrol information to be used for controlling a zooming operation ofthe aforesaid external variator lens means according to the inputtedexternal zoom operating information and the inputted zoom positioninformation and the internal zoom operating information received fromthe aforesaid zoom operating means.

[0028] Moreover, according to still another aspect of the presentinvention, there is provided an imaging system that comprises a lensdevice having a variator lens means for performing a zooming operation,lens-side zoom operating means for operating the aforesaid variator lensmeans, lens-side information output means for outputting lens-side zoomoperating information and zoom position information on a zoom positionof the aforesaid variator lens means, which are received from theaforesaid lens-side zoom operating means, lens-side information inputmeans for receiving optical zoom control information to be used forcontrolling the aforesaid variator lens means, and variator controlmeans for controlling a zooming operation of the aforesaid variator lensmeans according to the received control information, and that furtherhas an imaging apparatus having imaging means for imaging an object andfor outputting an image signal, camera-body-side information input meansfor receiving the lens-side zoom operating information and zoom positioninformation from the aforesaid lens-side information output means,camera-body-side zoom operating means for receiving camera-body-sidezoom operating information to be supplied to the aforesaid variator lensmeans, and camera-body-side information output means for generatingoptical zooming control information to be used to control a zoomingoperation of the aforesaid variator lens means, according to thereceived lens-side zoom operating information and the received zoomposition information and the camera-body-side zoom operating informationand for outputting the optical zooming control information to theaforesaid lens-side information input means.

[0029] Furthermore, according to yet another aspect of the presentinvention, there is provided a computer readable storage medium forstoring a program causing a computer to execute the steps of outputtingoperation information, which is obtained when a variator lens isoperated, and zoom position information which represents a zoom positionof the aforesaid variator lens, inputting control information, which isused for controlling the aforesaid variator lens, from an externaldevice, and controlling the aforesaid variator lens according to theinputted control information.

[0030] Further, according to still another aspect of the presentinvention, there is provided a computer readable storage medium forstoring a program causing a computer to execute the steps of imaging anobject and outputting an image signal, receiving external zoom operatinginformation and zoom position information to be supplied to an externalvariator lens, receiving internal zoom operating information to besupplied to the aforesaid external variator lens, and generating andoutputting optical zooming control information to be used forcontrolling a zooming operation of the aforesaid external variator lensaccording to the inputted external zoom operating information and theinputted zoom position information and the internal zoom operatinginformation.

[0031] Further, according to yet another aspect of the presentinvention, there is provided a lens device which comprises variator lensmeans for performing a zooming operation, zoom operating means foroperating the aforesaid variator lens means, information output meansfor outputting first zoom operating information, which is received fromthe aforesaid zoom operating means, and zoom position informationrepresenting a zoom position of the aforesaid variator lens means,information input means for receiving second zoom operating informationand zooming inhibition information from an external device, and variatorcontrol means for controlling a zooming operation of the aforesaidvariator lens means according to the first zoom operating information,the inputted second zoom operating information and the inputted zoominginhibition information.

[0032] Moreover, according to still another aspect of the presentinvention, there is provided a camera apparatus which comprises imagingmeans for imaging an object and for outputting an image signal,information input means for receiving first zoom operating informationand zoom position information to be supplied to external variator lensmeans, zoom operating means for receiving second zoom operatinginformation to be supplied to the aforesaid external variator lensmeans, information output means for outputting the second zoomingcontrol information and optical zooming inhibition information to beused for inhibiting a zooming operation of the aforesaid externalvariator lens means, electronic zooming means for performing electronicenlargement processing on an image represented by the image signal, andelectronic zooming control means for controlling the aforesaidelectronic zooming means according to the first zoom operatinginformation, the zoom position information and the second zoom operatinginformation.

[0033] Furthermore, according to yet another aspect of the presentinvention, there is provided a camera system which comprises a lensdevice having a variator lens means for performing a zooming operation,lens-side zoom operating means for operating the aforesaid variator lensmeans, lens-side information output means for outputting first zoomoperating information, which is received from the aforesaid lens-sidezoom operating means, and zoom position information on a zoom positionof the aforesaid variator lens means, lens-side information input meansfor receiving second zoom operating information and zooming inhibitioninformation from an external device and variator control means forcontrolling a zooming operation of the aforesaid variator lens meansaccording to the received second zoom operating information and thezooming inhibition information and the first zoom operating information,and further comprises an imaging apparatus having imaging means forimaging an object and for outputting an image signal, camera-body-sideinformation input means for receiving the first zoom operatinginformation and zoom position information from the aforesaid lens-sideinformation output means, camera-body-side zoom operating means forreceiving the second zoom operating information to be supplied to theaforesaid variator lens means, and camera-body-side information outputmeans for outputting the aforesaid lens-side information input means thesecond zoom operating information and the optical zooming inhibitionwhich is used for inhibiting the aforesaid variator lens means fromperforming a zooming operation, electronic zooming means for performingelectronic enlargement processing on an image represented by the imagesignal, and electronic zooming control means for controlling theaforesaid electronic zooming means according to the first zoom operatinginformation, the zoom position information and the second zoom operatinginformation.

[0034] Further, according to still another aspect of the presentinvention, there is provided a computer readable storage medium forstoring a program causing a computer to execute the steps of outputtingfirst zoom operating information, which is obtained when a variator lensis operated, and zoom position information which represents a zoomposition of the aforesaid variator lens, inputting second zoom operatinginformation and zooming inhibition information, which are received froman external device, and controlling the aforesaid variator lensaccording to the inputted second zoom operating information, theinputted zooming inhibition information and the first zoom operatinginformation.

[0035] Moreover, according to yet another aspect of the presentinvention, there is provided a computer readable storage medium forstoring a program causing a computer to execute the steps of imaging anobject and outputting an image signal, receiving first zoom operatinginformation and zoom position information to be supplied to an externalvariator lens, receiving second zoom operating information to besupplied to the aforesaid external variator lens, outputting the secondzooming control information and optical zooming inhibition informationto be used for inhibiting the aforesaid external variator lens fromperforming a zooming operation, and performing electronic zooming forelectronically enlarging an image represented by the image signalaccording to the first zoom operating information and the second zoomoperating information and the zoom position information.

[0036] Furthermore, according to still another aspect of the presentinvention, there is provided a lens control system which comprises afirst device having optical variator means for optically changing amagnification of an image, a second device having electronic variatormeans for electronically enlarging an image by signal processing, andfirst and second variator operating members respectively provided in theaforesaid first and second devices. In this lens control system, whenthe aforesaid optical variator means is operated, the aforesaid opticalvariator means is controlled in the aforesaid first device according toinformation for operating the aforesaid first and second variatoroperating members. Further, when the aforesaid electronic variator meansis operated, the aforesaid electronic variator means is controlled inthe aforesaid second device according to information for operating theaforesaid first and second variator operating members. Furthermore,during the aforesaid electronic variator means is operated, theaforesaid first device inhibits the aforesaid optical variator meansfrom operating.

[0037] Further, according to yet another aspect of the presentinvention, there is provided a camera system which comprises a lensdevice having an optical variator lens for optically changing amagnification of an image, a camera device having electronic variatormeans for electronically enlarging an image by signal processing, alens-device-side variator operating member, and a camera-device-sidevariator operating member. In this camera system, when the aforesaidoptical variator lens is operated, the aforesaid optical variator lensis controlled in the aforesaid lens device according to information foroperating the aforesaid lens-device-side and camera-device-side variatoroperating members. Further, when the aforesaid electronic variator meansis operated, the aforesaid electronic variator means is controlled inthe aforesaid camera device according to information for operating theaforesaid lens-device-side and camera-device-side variator operatingmembers. Moreover, during the aforesaid electronic variator means isoperated, a signal causing the aforesaid lens device to inhibit theaforesaid optical variator lens from operating is transmitted to theaforesaid lens device.

[0038] Furthermore, according to still another aspect of the presentinvention, there is provided a lens device which comprises variator lensmeans for performing a zooming operation, control means for controllingthe zooming operation of the aforesaid variator lens means, and signaloutput means for outputting an electronic zooming enabling signal and anelectronic zooming preparation signal for giving advance notice of theelectric zooming enabling signal, during the zooming operation.

[0039] Moreover, according to yet another aspect of the presentinvention, there is provided an imaging apparatus which comprisesimaging means for imaging an object and for outputting an image signal,electronic zooming means for electronically enlarging an imagerepresented by the image signal, signal input means for receiving anelectronic zooming preparation permission signal and an electroniczooming enabling signal, and control means for enabling control of theaforesaid electronic zooming means when each of the electronic zoomingpreparation permission signal and the electronic zooming enabling signalis received.

[0040] Further, according to still another aspect of the presentinvention, there is provided an imaging system which comprises a lensdevice having a variator lens means for performing a zooming operation,first control means for controlling the zooming operation of theaforesaid variator lens means, and signal output means for outputting anelectronic zooming enabling signal and an electronic zooming preparationpermission signal which gives advance notice of the electric zoomingenabling signal, during the zooming operation, and which furthercomprises an imaging apparatus having imaging means for imaging anobject and for outputting an image signal, electronic zooming means forperforming electronic enlargement processing on an image represented bythe image signal, signal input means for receiving an electronic zoomingpreparation permission signal and an electronic zooming enabling signal,and second control means for enabling control of the aforesaidelectronic zooming means when each of the electronic zooming preparationpermission signal and the electronic zooming enabling signal isreceived.

[0041] Furthermore, according to yet another aspect of the presentinvention, there is provided a computer readable storage medium forstoring a program causing a computer to execute the steps of controllinga zooming operation performed by a variator lens, and outputting anelectronic zooming enabling signal and an electronic zooming preparationpermission signal which gives advance notice of the electric zoomingenabling signal, during the zooming operation.

[0042] Moreover, according to still another aspect of the presentinvention, there is provided a computer readable storage medium forstoring a program causing a computer to execute the steps of imaging anobject and outputting an image signal, performing electronic zooming forelectronically enlarging an image represented by the image signal,receiving an electronic zooming preparation permission signal and anelectronic zooming enabling signal, and enabling the electronic zoomingwhen each of the electronic zooming preparation permission signal andthe electronic zooming enabling signal is received.

[0043] Further, according to yet another aspect of the presentinvention, there is provided an imaging apparatus which comprisesimaging means, electronic zooming means for enlarging an image taken bythe aforesaid imaging means, zoom input means for receiving zoomoperating information, lens information input means for receiving firstzoom information, which indicates presence or absence of an opticalzooming mechanism in an external lens means, and second zoom informationwhich indicates presence or absence of an optical zooming mechanism,which does not operate in response to a control signal received from anexternal device, in the aforesaid external lens means, control outputmeans for outputting an optical zooming control signal which instructsthe aforesaid external lens means to perform a zooming operation andcontrol means for controlling the aforesaid optical zooming mechanism ofthe aforesaid external lens means through the aforesaid electroniczooming means and the aforesaid lens control output means according tothe zoom operating information inputted to the aforesaid zoom inputmeans in such a manner as to be able to be driven, in a case that thefirst zoom information indicates the presence of the aforesaid opticalzooming mechanism and that the second zoom information indicates theabsence of the aforesaid optical zooming mechanism, and for controllingthe aforesaid electronic zooming means in such a manner as to be able tobe driven, in a case that the first zoom information indicates theabsence of the aforesaid optical zooming mechanism, and for controllingthe aforesaid electronic zooming means in such a manner as not to bedriven, in a case that the second zoom information indicates thepresence of the aforesaid optical zooming mechanism.

[0044] Furthermore, according to still another aspect of the presentinvention, there is provided an imaging apparatus which comprisesimaging means, electronic zooming means for enlarging an image taken bythe aforesaid imaging means, zoom input means for receiving zoomoperating information, lens information input means for receiving zoominformation, which indicates presence or absence of an optical zoomingmechanism in an external lens means, and specific lens group informationwhich indicates whether the aforesaid external lens means belongs to aspecific lens group, control output means for outputting an opticalzooming control signal which instructs the aforesaid external lens meansto perform a zooming operation, and control means for controlling theaforesaid optical zooming mechanism of the aforesaid external lens meansthrough the aforesaid electronic zooming means and the aforesaid lenscontrol output means according to the zoom operating informationinputted to the aforesaid zoom input means in such a manner as to beable to be driven, in a case where the zoom information indicates thepresence of the aforesaid optical zooming mechanism and where thespecific lens group information indicates that the aforesaid externallens means does not belong to the aforesaid specific lens group, and forcontrolling the aforesaid electronic zooming means in such a manner asto be able to be driven, in a case where the zoom information indicatesthe absence of the aforesaid optical zooming mechanism, and forcontrolling the aforesaid electronic zooming means in such a manner asnot to be driven, in a case where the specific lens group informationindicates that the aforesaid external lens means belongs to theaforesaid specific lens group.

[0045] Other features, objects and advantages of the present inventionwill become apparent from the following description of preferredembodiments with reference to the drawings in which like referencecharacters designate like or corresponding parts throughout severalviews.

BRIEF DESCRIPTION OF THE DRAWINGS

[0046]FIG. 1 is a flowchart illustrating processing concerning a zoomingoperation, which is performed by a lens microcomputer of a firstembodiment of the present invention;

[0047]FIG. 2 is a flowchart illustrating processing concerning a zoomingoperation, which is performed by a camera microcomputer of the firstembodiment of the present invention;

[0048]FIG. 3 is a block diagram showing the configuration of alens-interchangeable video camera according to the first embodiment ofthe present invention;

[0049]FIG. 4 is a block diagram showing the configuration of theconventional lens-interchangeable video camera;

[0050]FIGS. 5A and 5B are diagrams illustrating electronic zooming bythe conventional video camera;

[0051]FIG. 6 is a block diagram showing the configuration of theenlargement processing circuit of the conventional video camera;

[0052]FIG. 7 is a flowchart illustrating the processing to be performedby the camera microcomputer of the conventional video camera;

[0053]FIG. 8 is a flowchart illustrating the processing concerningcommunication to be performed by the camera microcomputer of theconventional video camera;

[0054]FIG. 9 is a flowchart illustrating the processing concerningzooming to be performed by the camera microcomputer of the conventionalvideo camera;

[0055]FIG. 10 is a flowchart illustrating the processing concerningzooming to be performed by the lens microcomputer of the conventionalvideo camera;

[0056]FIG. 11 is a flowchart illustrating processing concerning zoomingto be performed by a lens microcomputer of a second embodiment of thepresent invention;

[0057]FIG. 12 is a flowchart illustrating processing concerning zoomingto be performed by a camera microcomputer of the second embodiment ofthe present invention;

[0058]FIG. 13 is a block diagram showing another example of theconfiguration of the enlargement processing circuit of the conventionalvideo camera;

[0059]FIG. 14 is a diagram illustrating results of an actual zoomingoperation that is conducted according to processing performed by lensand camera microcomputers of the second embodiment of the presentinvention;

[0060]FIG. 15 is a block diagram showing the configuration of alens-interchangeable video camera according to a third embodiment of thepresent invention;

[0061]FIG. 16 is a flowchart illustrating processing concerning azooming operation, which is performed by a lens microcomputer of thethird embodiment of the present invention;

[0062]FIG. 17 is a flowchart illustrating processing concerning azooming operation, which is performed by a camera microcomputer of thethird embodiment of the present invention;

[0063]FIG. 18 is a diagram illustrating results of an actual zoomingoperation that is conducted according to processing performed by thelens and camera microcomputers of the third embodiment of the presentinvention;

[0064]FIG. 19 is a diagram showing the configuration of aninterchangeable lens unit;

[0065]FIG. 20 is a diagram showing the configuration of anotherinterchangeable lens unit;

[0066]FIG. 21 is a flowchart detailedly illustrating zooming processingto be performed by a camera microcomputer of a fourth embodiment of thepresent invention;

[0067]FIG. 22 is a flowchart illustrating zooming processing to beperformed by a camera microcomputer of the interchangeable lens unit ofFIG. 19 in the fourth embodiment of the present invention;

[0068]FIG. 23 is a flowchart illustrating zooming processing to beperformed by a camera microcomputer of the interchangeable lens unit ofFIG. 20 in the fourth embodiment of the present invention;

[0069]FIG. 24 is a flowchart illustrating zooming processing to beperformed by a camera microcomputer of the interchangeable lens unit ofFIG. 4 in the fourth embodiment of the present invention;

[0070]FIG. 25 is a flowchart detailedly illustrating zooming processingto be performed by a camera microcomputer of a fifth embodiment of thepresent invention;

[0071]FIG. 26 is a flowchart illustrating zooming processing to beperformed by the camera microcomputer of the interchangeable lens unitof FIG. 19 in the fifth embodiment of the present invention;

[0072]FIG. 27 is a flowchart illustrating zooming processing to beperformed by the camera microcomputer of the interchangeable lens unitof FIG. 20 in the fifth embodiment of the present invention; and

[0073]FIG. 28 is a flowchart illustrating zooming processing to beperformed by the camera microcomputer of the interchangeable lens unitof FIG. 4 in the fifth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0074] Hereinafter, the preferred embodiments of the present inventionwill be described in detail with reference to the accompanying drawings.

[0075] (First Embodiment)

[0076] A lens-interchangeable video camera used for the first embodimentof the present invention is constituted as illustrated in FIG. 3. InFIGS. 3 and 4, same reference numerals designate substantially the sameconstituent elements. Operating information of a zoom ring 116(lens-side zoom key information) is inputted to a lens microcomputer115. It is detected in the lens microcomputer 115 which of tele-side andwide-side zooming directions corresponds to a direction in which thezoom ring 116 is operated.

[0077] Further, a program for performing processing in the lensmicrocomputer 115 according to the flowchart of FIG. 1 is stored in astorage medium 117. Moreover, programs for performing processing in thecamera microcomputer 208 according to the flowcharts of FIGS. 2, 7 and 8are stored in a storage medium 214. Semiconductor memories, opticaldisks, magneto-optic disks or magnetic media may be used as thesestorage media 117 and 214.

[0078] Next, processing to be performed by the lens microcomputer 115 ofthe first embodiment of the present invention will be described.

[0079]FIG. 1 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. In step 801, the processing is started.Then, in step 802, the lens microcomputer 115 checks whether a zoom lensstop request signal comes thereto from a camera microcomputer 208. Ifthe zoom lens stop request signal has already come thereto, controlproceeds to step 808. Otherwise, control advances to step 803 whereuponthe lens microcomputer 115 checks according to the information sent bythe camera microcomputer 208 which of the tele direction and the widedirection the moving direction of the zoom lens group is. If the movingdirection of the zoom lens group is the tele direction, control proceedsto step 804. If the wide direction, control advances to step 805.

[0080] In step 804, the lens microcomputer 115 checks whether the zoomlens group is positioned at the tele end. If so, control proceeds tostep 808. Otherwise, control advances to step 806. Further, in step 805,the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step 808.Otherwise, control advances to step 806. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step 806. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in step 807.Furthermore, in step 808, the zoom lens group is stopped.

[0081] Upon completion of the operation performed in step 807 or 808,the lens microcomputer 115 checks in step 809 whether the zoom lensgroup is placed at the tele end. If so, control proceeds to step 810.Otherwise, control advances to step 811. In step 810, the lensmicrocomputer 115 sends the camera microcomputer 208 an electroniczooming enabling signal. Further, in step 811, the lens microcomputer115 sets optical tele end information to be sent to the cameramicrocomputer 208. Then, control proceeds to step 812. Furthermore, instep 811, the lens microcomputer 115 clears optical tele end informationto be sent to the camera microcomputer 208. Then, control advances tostep 812 whereupon the lens microcomputer 115 detects the operatingcondition of the zoom ring. Moreover, the lens microcomputer 115provides a setting for sending the camera microcomputer 208 thelens-side zoom key information indicating that the zoom ring 116 is notoperated, or that the zoom ring 116 is operated in a directioncorresponding to the tele or wide side. Then, control proceeds to step813. In this step, control returns to a main routine.

[0082] Next, processing to be performed in the camera microcomputer 208of the first embodiment of the present invention will be described. Theflow of the processing to be performed by the camera microcomputer 208is broadly similar to the flow illustrated in FIGS. 7 and 8.

[0083] Step 406 of a process flow of the camera microcomputer 208 willbe described in detail with reference to a flowchart of FIG. 2. In step901, the processing is started. Then, in step 902, the cameramicrocomputer 208 checks the lens-side zoom key information sent fromthe lens microcomputer 115. If the zoom ring 116 is not operated,control advances to step 901. Otherwise, control proceeds to step 904whereupon the camera microcomputer 208 further checks the lens-side zoomkey information sent from the lens microcomputer 115. If the zoom ring116 is operated in a direction corresponding to the tele side, controladvances to step 906. If the zoom ring 116 is operated in a directioncorresponding to the wide side, control proceeds to step 908. On theother hand, in step 905, the camera microcomputer 208 checks which ofthe switches 210 and 211 is pushed in the camera body unit 100. If the“TELE” switch 210 is pushed, control advances to step 906. Conversely,if the “WIDE” switch 211 is pushed, control proceeds to step 908.

[0084] In step 906, the camera microcomputer 208 judges from opticaltele end information sent from the lens microcomputer 115 whether thezoom lens group is positioned at the optical tele end. If so, controladvances to step 907. Otherwise, control proceeds to step 910. Then, instep 907, the camera microcomputer 208 checks whether the zoom lensgroup is placed at the tele end in the case of electronic zooming. Ifso, control advances to step 911. Otherwise, control proceeds to step909. On the other hand, in step 908, the camera microcomputer 208 checkswhether an electronic zooming operation is currently being performed. Ifso, control advances to step 909. Otherwise, control proceeds to step912.

[0085] In this step 912, the camera microcomputer 208 establishes asetting for sending the lens microcomputer 115 a request signal to beused for moving the zoom lens group to the wide side. Further, in step909, an electronic zooming operation is performed by increasing ordecreasing the aforementioned interpolation coefficients according towhich of the switches 210 and 211 is pushed. Moreover, the cameramicrocomputer 208 controls the enlargement processing circuit 205according to a result of the electronic zooming operation. Then, controladvances to step 911 whereupon the camera microcomputer 208 provides asetting for sending the lens microcomputer 115 a zoom lens stop requestsignal. On the other hand, the camera microcomputer 208 establishes asetting for sending the lens microcomputer 115 a request signal to beused for moving the zoom lens group to the tele side. Upon completion ofthe operation to be performed in one of the aforementioned steps 910,911 and 912, control returns to the main routine in step 913.

[0086] Incidentally, it has been described that this embodiment isadapted to detect the zoom operating direction (namely, detect that thezoom lens group is operated toward the tele side or toward the wideside). However, the present invention is easily applied to a case thatthe camera has multi-zooming-speed in each zoom operating direction.

[0087] Further, even in the case that the camera body unit has aplurality of zoom operating means or that an external input device, suchas a remote control device, for a camera body unit has zoom lensoperating means, the present invention is easily applied to such a caseby handling these means as a single zoom operating means in the camerabody unit.

[0088] As described above, according to the first embodiment, even if azoom operating means such as a zoom ring is provided therein, theoperating information and the zoom position information are outputted toan external camera. Moreover, a zooming operation is performed accordingto control information provided by the camera. At that time, the controlinformation is generated in the camera body unit according to theoperating information, the zoom position information and zoom operatinginformation produced by a zooming operation of the camera body unit.Thus, even if the zoom operating means are provided in both the lensunit and the camera body unit, respectively, the camera smoothlyperforms suitable zooming control operations.

[0089] Furthermore, according to the first embodiment, the operatinginformation and the zoom position information are generated by a zoomingoperation of the lens unit and inputted to the camera body unit. Then,optical zooming control information is generated according to suchinputted information and internal zoom operating information produced bythe camera body unit. Subsequently, the optical zooming controlinformation is sent to the lens unit. Thus, even if the zoom operatingmeans are provided in both the lens unit and the camera body unit,respectively, the camera smoothly performs suitable zooming controloperations. Furthermore, the camera suitably performs electronic zoomingaccording to the aforementioned information.

[0090] (Second Embodiment)

[0091] A lens-interchangeable video camera used in this secondembodiment is constructed in such a manner as to be similar to the videocamera used in the first embodiment illustrated in FIG. 3. The videocamera of the second embodiment is different from that of the firstembodiment only in operations thereof. Thus, only the differencetherebetween will be described.

[0092] In the case of a video camera in which a zoom ring 116 to be usedfor manually performing a zooming operation is provided in aninterchangeable lens unit 100 as shown in FIG. 3, an operating conditionthereof caused by switches is not uniquely determined. Thus, such avideo camera has the problem that it is difficult to achieve suitableand smooth control of optical and electronic zooming operations. Thesecond embodiment aims at solving this problem.

[0093] Hereinafter, the second embodiment will be described withreference to the accompanying drawings.

[0094] In the case of the second embodiment, a program for performingprocessing, which includes an operation to be performed in the lensmicrocomputer 115 according to the flowchart of FIG. 11, is stored in astorage medium 117 shown in FIG. 3. Moreover, programs for performingprocessing in the camera microcomputer 208 according to the flowchartsof FIGS. 12, 7 and 8 are stored in a storage medium 214. Se conductormemories, optical disks, magneto-optic disks or magnetic media may beused as these storage media 117 and 214.

[0095] Next, processing to be performed in the lens microcomputer 115 ofthe second embodiment of the present invention will be described.

[0096]FIG. 11 is a flowchart illustrating processing concerning azooming operation, which is a part of the entire processing to beperformed by the lens microcomputer 115. In step 1001, the processing isstarted. Then, in step 1002, the lens microcomputer 115 checks whetheran optical zooming inhibition signal comes thereto from a cameramicrocomputer 208. If the optical zooming inhibition signal has alreadycome thereto, control proceeds to step 1009. Otherwise, control advancesto step 1003 whereupon the lens microcomputer 115 checks whether a zoomring 110 of the interchangeable lens unit 100 is operated. If so,control proceeds to step 1006. Otherwise, control advances to step 1004.

[0097] In step 1004, the lens microcomputer 115 checks according to theinformation sent by the camera microcomputer 208 whether zoom switches210 and 211 of a camera body unit 200 are operated. If so, controlproceeds to step 1005. Otherwise, control advances to step 1009. In step1005, the lens microcomputer 115 judges from the information sent by thecamera microcomputer 208 which of the tele direction and the widedirection the operating direction in which the zoom lens group isoperated. If such an operating direction of the zoom lens group is thetele direction, control proceeds to step 1008. If the wide direction,control advances to step 1007. On the other hand, in step 1006, the lensmicrocomputer 115 judges which of the tele direction and the widedirection corresponds to the operating direction in which the zoom ring116 is operated. If such an operating direction of the zoom ring 116corresponds to the tele direction, control proceeds to step 1008. Ifcorresponding to the wide direction, control advances to step 1007.

[0098] In step 1008, the lens microcomputer 115 checks whether the zoomlens group is positioned at the tele end. If so, control proceeds tostep 1009. Otherwise, control advances to step 1010. Further, in step1007, the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step 1009.Otherwise, control advances to step 1010. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step 1010. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in step 1011.

[0099] Furthermore, in step 1009, the zoom lens group is stopped.

[0100] Upon completion of the operation performed in step 1009 or 1011,the lens microcomputer 115 checks in step 1012 whether the zoom lensgroup is placed at the tele end. If so, control proceeds to step 1013.Otherwise, control advances to step 1014. In step 1013, the lensmicrocomputer 115 sets optical tele end information to be sent to thecamera microcomputer 208. Then, control proceeds to step 1015.Furthermore, in step 1014, the lens microcomputer 115 clears opticaltele end information to be sent to the camera microcomputer 208. Then,control advances to step 1015 whereupon the lens microcomputer 115detects the operating condition of the zoom ring 116. Moreover, the lensmicrocomputer 115 provides a setting for sending the cameramicrocomputer 208 the lens-side zoom key information indicating that thezoom ring 116 is not operated, or that the zoom ring 116 is operated ina direction corresponding to the tele or wide side. Then, controlproceeds to step 1016. In this step, control returns to a main routine.

[0101] Next, processing to be performed in the camera microcomputer 208of the second embodiment of the present invention will be described. Theflow of the processing to be performed by the camera microcomputer 208is broadly similar to the flow illustrated in FIGS. 7 and 8.

[0102] Step 406 of a process flow of the camera microcomputer 208 willbe described in detail with reference to a flowchart of FIG. 12. In step1101, the processing is started. Then, in step 1102, the cameramicrocomputer 208 checks the zoom switches 210 and 211 of the camerabody unit 100. Further, the camera microcomputer 208 makes preparationsfor sending the lens microcomputer 115 a signal indicating that the zoomswitches 210 and 211 are not operated or that the zoom switches 210 and211 are operated in the tele or wide direction.

[0103] In step 1103, the camera microcomputer 208 checks the lens-sidezoom key information sent from the lens microcomputer 115. If the zoomring 116 is not operated, control advances to step 1104. Otherwise,control proceeds to step 1105 whereupon the camera microcomputer 208further checks the lens-side zoom key information sent from the lensmicrocomputer 115. If the zoom ring 116 is operated in a directioncorresponding to the tele side, control advances to step 1107. If thezoom ring 116 is operated in a direction corresponding to the wide side,control proceeds to step 1109. On the other hand, in step 1104, thecamera microcomputer 208 checks whether the switches 210 and 211 arepushed in the camera body unit 100. If so, control advances to step1106. Otherwise, control proceeds to step 1111. In step 1106, the cameramicrocomputer 208 checks which of the switches 210 and 211 is pushed inthe camera body unit 100. If the “TELE” switch 210 is pushed, controladvances to step 1107. Conversely, if the “WIDE” switch 211 is pushed,control proceeds to step 1109.

[0104] In step 1107, the camera microcomputer 208 judges from opticaltele end information sent from the lens microcomputer 115 whether thezoom lens group is positioned at the optical tele end. If so, controladvances to step 1108. Otherwise, control proceeds to step 1112. Then,in step 1108, the camera microcomputer 208 checks whether the zoom lensgroup is placed at the tele end in the case of electronic zooming. Ifso, control advances to step 1111. Otherwise, control proceeds to step1110. On the other hand, in step 1109, the camera microcomputer 208checks whether an electronic zooming operation is currently beingperformed. If so, control advances to step 1110. Otherwise, controlproceeds to step 1112.

[0105] In step 1110, an electronic zooming operation is performed byincreasing or decreasing the aforementioned interpolation coefficientsaccording to which of the switches 210 and 211 is pushed. Moreover, thecamera microcomputer 208 controls an enlargement processing circuit 205according to a result of the electronic zooming operation. Then, controladvances to step 1111 whereupon the camera microcomputer 208 provides asetting for sending the lens microcomputer 115 an optical zoominginhibition signal. Subsequently, control proceeds to step 1112 whereuponcontrol returns to the main routine.

[0106] Incidentally, it has been described that the second embodiment isadapted to detect the zoom operating direction (namely, detect that thezoom lens group is operated toward the tele side or toward the wideside). However, the present invention is easily applied to a case thatthe camera has multi-zooming-speed in each zoom operating direction.

[0107] Further, even in the case that the camera body unit has aplurality of zoom operating means or that an external input device, suchas a remote control device, for a camera body unit has zoom lensoperating means, the present invention is easily applied to such a caseby handling these means as a single zoom operating means in the camerabody unit.

[0108] As described above, according to the second embodiment, even if azoom operating means such as a zoom ring is provided therein, a zoomingoperation is controlled in accordance with the corresponding firstoperating information and the zoom position information and the zoominginhibition information. At that time, a zooming operation is controlledby the camera body unit according to the first operating information,the zoom position information and second zoom operating informationproduced by a zooming operation of the camera body unit. Thus, even ifthe zoom operating means are provided in both the lens unit and thecamera body unit, respectively, the camera smoothly performs suitablezooming control operations.

[0109] Furthermore, according to the second embodiment, the firstoperating information and the zoom position information are generated bya zooming operation of the lens unit and inputted to the camera bodyunit. Thus, an electronic zooming operation is performed according tosuch inputted information and second zoom operating information producedby the camera body unit. Moreover, the second zoom operating informationand the optical zooming control information are generated and sent tothe lens unit. Thus, even if the zoom operating means are provided inboth the lens unit and the camera body unit, respectively, the camerasmoothly performs suitable zooming control operations.

[0110] (Third Embodiment)

[0111] Video cameras having both the optical zooming function and theelectronic zooming function, similarly as the first and secondembodiments, have the problem that it is difficult to smoothly switchbetween the optical zooming function and the electronic zoomingfunction. Hereinafter, this problem will be described by taking theconventional video camera shown in FIG. 4 as an example.

[0112]FIG. 13 shows the configuration of the enlargement processingcircuit 205 of the conventional video camera illustrated in FIG. 4. Forsimplicity of description, this figure illustrates only verticalenlargement processing.

[0113] As shown in FIG. 10, an input video signal 300 is stored in amemory circuit 301 under the control of a emory control signalgenerating circuit 302 and sent to an output switch circuit 309.Microcomputer interface circuit 304 receives an enlargementmagnification and enlargement information from a camera microcomputer208. Based on this, an enlarged magnification determining circuit 303outputs the enlargement magnification to the memory control signalgenerating circuit 302 and an interpolation coefficient generatingcircuit 308. The memory control signal generating circuit 302 readssignals, which respectively represent an nth line and an (n−1)th linedelayed by 1 H from the nth line, from the memory circuit 301. Theinterpolation coefficient generating circuit 308 generates interpolationcoefficients corresponding to the enlargement magnification and givesthe generated interpolation coefficients to multipliers 305 and 306.These multipliers multiply the signals, which respectively represent annth line and an (n−1)th line, by the interpolation coefficients. Outputsof these multipliers are added up in an adder 307. Resultant signal isoutputted therefrom to the output switch circuit 309. Then, the outputswitch circuit 309 outputs the signal sent from the adder 307 or theinput video signal 300 according to a switch signal sent from themicrocomputer interface circuit 304 as an output video signal 310.

[0114] However, in the conventional circuit, it is difficult to set thetiming of the switching between optical zooming, which is performed inthe interchangeable lens unit, and enlargement processing which isperformed by utilizing the electronic zooming in the camera body unit.Moreover, for some reason, the conventional circuit has no means (forexample, a process sequence) for discontinuing the enlargementprocessing in the camera body unit (for instance, in the case that theinterchangeable lens unit has a zoom ring for mechanically moving thevariator lens and that a gear has a slip mechanism for transmitting themovement of the zoom ring to the rotation shaft, a cameraman operatesthe zoom ring in a direction corresponding to the wide side).

[0115] Thus, in Japanese Unexamined Patent Publication No. 9-96756Official Gazette, the inventors of the present invention have proposeddevices to solve the aforementioned problem. Consequently, smoothswitching between optical and electronic zooming operations is achieved.However, troubles, such as suspension of a zooming operation, may happenin the cases that a delay occurs in transmission of an electroniczooming inhibition or permission signal between the lens unit and thecamera body unit due to some cause and that, after an electronic zoomingenabling signal is received by the camera body unit, a delay occurstherein until electronic zooming is performed therein.

[0116] Hereinafter, this phenomenon will be described in detail.

[0117]FIG. 14 is a diagram illustrating the timing with which an outputvideo signal is changed from video signals of an optical zooming regionto those of an electronic zooming region when a zooming operation isperformed from the wide side to the tele side. In this diagram, thetransverse axis represents time. As viewed in this diagram, the righterthe position of a time point on the transverse axis becomes, the latertime the time point indicates.

[0118] In FIG. 14, reference numeral 801 denotes a row representing asequence of fields of a standard television signal. Fields (n−1) to(n+4) are shown in this figure. Reference numeral 802 designates a rowshowing various kinds of processing to be performed by the cameramicrocomputer 208 in the respective fields. The aforementioned kinds ofprocessing illustrated in FIG. 7 are performed in the respective fields.Reference numeral 803 designates a row showing the field Nos. of fieldsin which the input video signals 300 are obtained by photoelectricconversion. Incidentally, a field, in which a video signal is read froman imager 201, is just subsequent to a field in which this video signalis obtained by photoelectric conversion. Thus, the field No. of thisfield is smaller than the field No. thereof shown in the row 801 by 1.

[0119] Reference numeral 804 designates a row showing the field No. of afield in which an output signal of the adder 307 is obtained in theimager 201 by photoelectric conversion. However, an output signal of theadder 307 is indefinite until a video signal is fetched in the memorycircuit 301. After a video signal is fetched thereto, a signal delayedby 1 field is outputted from the adder 307. Reference numeral 805denotes a row indicating which of the input video signal 300 and theoutput signal of the adder 307 is selected by the output switch circuit309 according to a switch signal outputted from the microcomputerinterface circuit 304 shown in FIG. 13. Reference numeral 806 designatesa row indicating the field No. of a field in which the output videosignal 310 is obtained in the imager 201 by photoelectric conversion.

[0120] Next, a process flow of the zooming processing will be describedby concentrating on the processing to be performed by the cameramicrocomputer 208.

[0121] During the zooming operation from the wide side to the tele side,the lens microcomputer 115 prepares electronic zooming permissioninformation for the next communication with the camera microcomputer 208in the field n when the optical zoom lens reaches the optical tele endat the time t(n)1.

[0122] In the field (n+1), an electronic zooming enabling signal is sentfrom the lens microcomputer 115 to the camera microcomputer 208 by thecommunication performed at the time t(n)1. In the zooming processing atthe time t(n+1)2, the camera microcomputer 208 performs an operation forcausing the memory circuit 301 to store the input video signal in thetime (n+2).

[0123] In the field (n+2), an operation for causing the input videosignal 300 obtained in the field (n+3) to be stored in the memorycircuit 301 is performed. Moreover, operations of enlarging an image,which is represented by the stored input video signal 300 in the field(n+2), in the field (n+3), and of outputting a video signal (n+1)′representing an enlarged image, and of selecting a received output ofthe adder 307 as an output of the output switch circuit 309.

[0124] In the field (n+3), an operation of storing the input videosignal 300, which is obtained in the field (n+4), in the memory circuit301 is performed during the zooming processing at the time t(n+3).Further, the circuit performs operations of enlarging an image, which isrepresented by the stored input video signal 300 in the field (n+2), inthe field (n+3), and of outputting a video signal (n+1)′ representing anenlarged image, and of selecting a received output of the adder 307 asan output of the output switch circuit 309. Further, the circuitperforms operations of enlarging an image, which is represented by thestored input video signal 300 in the field (n+3), in the field (n+4),and of outputting a video signal (n+1)′ representing an enlarged image,and of outputting a video signal (n+2)′ to the output switch circuit309. In and after the field (n+4), the same processing as performed inthe field (n+3) is carried out.

[0125] Next, change 806 in the output video signal 310 with time will bedescribed. Because the zoom lens reaches the optical tele end in thefield “n”, signals obtained in the imager 201 by photoelectricconversion in the fields up to (n−1) and signals obtained byphotoelectric conversion in the field “n”, in which the optical zoomingis ceased in the middle thereof, are video signals obtained during theoptical zooming. Thus, the output video signals outputted in the fieldsup to (n+1) are signals outputted during the optical zooming. Signalsobtained in the field (n+1) by photoelectric conversion are outputtedwithout change as the output video signal 310 in the field (n+2), andthus are neither signals obtained during the optical zooming, norsignals obtained during the electronic zooming. The output video signals310 outputted in the field (n+3) and the subsequent fields are obtainedby enlarging signals stored in the memory circuit 301 and are videosignals obtained during the electronic zooming.

[0126] As is understood from the foregoing description, the zooming issuspended in the case that a time lag occurs between the reception ofthe electronic zooming enabling signal and the implementing of theelectronic zooming in the camera body unit.

[0127] This third embodiment aims at solving the aforementioned problemand at achieving the smooth switching between the optical zooming andthe electronic zooming.

[0128] Hereinafter, the third embodiment will be described withreference to the accompanying drawings.

[0129] A lens-interchangeable video camera used in the third embodimentis constructed in such a manner as to be similar to the video cameraused in the first embodiment illustrated in FIG. 4. The video camera ofthe second embodiment is different from that of FIG. 4 only in that thevideo camera of this embodiment has storage media 117 and 214 asillustrated in FIG. 15. Further, the flow of the processing to beperformed by the camera microcomputer 208 is broadly similar to the flowillustrated in FIGS. 7 and 8.

[0130] Further, the storage medium 117 stores a program for performing aprocess illustrated in a flowchart of FIG. 16, which is executed by thelens microcomputer 115. Moreover, the storage medium 117 stores aprogram for performing processes illustrated in flowcharts of FIGS. 17,7 and 8, which are executed by the camera microcomputer 208.Semiconductor memories, optical disks, magneto-optic disks or magneticmedia may be used as these storage media 117 and 214.

[0131] First, step 406 of a process flow (see FIG. 7) by the cameramicrocomputer 208 of the third embodiment of the present invention willbe described in detail with reference to FIG. 17. Incidentally, in thefollowing description, it is assumed that only the zoom switches 210 and211 move the variator lens group 102.

[0132] As shown in FIG. 17, in step 1201, the processing is started.Then, in step 1202, the camera microcomputer 208 checks whether azooming operation is being performed. Subsequently, if both the zoomswitches 210 and 211 are pushed, or if neither of these zoom switches ispushed, control advances to step 1207. If only one of these zoomswitches is pushed, control proceeds to step 1203 whereupon the cameramicrocomputer 208 further checks which of the switches 210 and 211 ispushed. If the “TELE” switch 210 is pushed, control advances to step1204. If the “WIDE” switch 211 is pushed, control proceeds to step 1208.

[0133] In step 1204, the camera microcomputer 208 judges whetherelectronic zooming permission information comes thereto from the lensmicrocomputer 115. If electronic zooming is permitted, control advancesto step 1205. Otherwise, control proceeds to step 1210. In step 1205,the camera microcomputer 208 checks whether the zoom lens group ispositioned at the optical tele end. If so, control advances to step1207. Otherwise, control proceeds to step 1206 whereupon an electroniczooming operation is performed by increasing or decreasing theaforementioned interpolation coefficients according to which of theswitches 210 and 211 is pushed. Moreover, the camera microcomputer 208controls the enlargement processing circuit 205 according to a result ofthe electronic zooming operation. Then, in step 1207, the cameramicrocomputer 208 sends a zoom lens stop request signal to the lensmicrocomputer 115.

[0134] On the other hand, in step 1208, the camera microcomputer 208checks whether an electronic zooming operation is currently beingperformed. If so, control advances to step 1206. Otherwise, in step1209, the camera microcomputer 208 sends the lens microcomputer 115 arequest signal for moving the zoom lens group in a directioncorresponding to the wide side.

[0135] Further, in step 1210, the camera microcomputer 208 checkswhether an electronic zooming preparation permission signal comesthereto from the lens microcomputer 115. If permitted, control advancesto step 1211. Otherwise, control proceeds to step 1212. In step 1211,the camera microcomputer 208 makes preparations for starting theelectronic zooming. Then, control advances to step 1212. Input imagesignal 300 is stored in the memory circuit 301 so that, owing to thepreparations made in step 1211, an electronic zooming operation can beperformed immediately after an electronic zooming permission signalcomes from the lens microcomputer 115. In step 1212, the cameramicrocomputer 208 sends the lens microcomputer 115 a request signal tobe used for moving the zoom lens group to the tele side. Upon completionof the operation to be performed in one of the aforementioned steps1207, 1212 and 1209, control returns to the main routine in step 1213.

[0136] Next, processing to be performed by the lens microcomputer 115 ofthe third embodiment will be described.

[0137]FIG. 16 is a flowchart illustrating processing concerning azooming operation, which is a part of the entire processing to beperformed by the lens microcomputer 115. Incidentally, a manual zoomingoperation will be described hereunder by way of example. In step 1301,the processing is started. Then, in step 1302, the lens microcomputer115 checks whether the zoom stop request signal comes thereto from thecamera microcomputer 208. If the zoom stop request signal has alreadycome thereto, control proceeds to step 1308. Otherwise, control advancesto step 1303 whereupon the lens microcomputer 115 checks from theinformation sent from the camera microcomputer 208 which of the teledirection and the wide direction the moving direction of the zoom lensgroup is. If the tele direction, control proceeds to step 1304.Conversely, if the wide direction, control advances to step 1305.

[0138] In step 1304, the lens microcomputer 115 checks whether the zoomlens group is positioned at the tele end. If so, control proceeds tostep 1308. Otherwise, control advances to step 1306. Further, the movingspeed of the zoom lens group and the moving speed and direction of thefocusing lens group are calculated in step 1306. According to a resultof this calculation, the zoom lens group and the focusing lens group aredriven in step 1307. Furthermore, in step 1308, the zoom lens group isstopped.

[0139] Upon completion of the operation performed in step 1307 or 1308,the lens microcomputer 115 checks in step 1309 whether the zoom lensgroup is placed at the tele end. If so, control proceeds to step 1310.Otherwise, control advances to step 1311. In step 1310, the lensmicrocomputer 115 sets information to be used for sending an electroniczooming permission signal to the camera microcomputer 208. Furthermore,in step 1311, the lens microcomputer 115 sets information to be used forsending an electronic zooming inhibition signal to the cameramicrocomputer 208. Then, control advances to step 1312.

[0140] In this step 1312, the lens microcomputer 115 checks whether thezoom lens group is moving to the wide side. If so, control proceeds tostep 1313. Otherwise, control advances to step 1315. In step 1313, thelens microcomputer 115 checks whether a current focal length f of thezoom lens group is not less than a focal length fn at which the zoomlens group would reach the tele end within ({fraction (1/60)}) secondsif the zoom lens group moved by maintaining a current zooming speed. Ifnot less than fn, control proceeds to step 1314. Otherwise, controladvances to step 1315. In step 1314, the lens microcomputer 115 setsinformation for sending an electronic zooming permission signal to thecamera microcomputer 208. Furthermore, in step 1315, the lensmicrocomputer 115 sets information for sending an electronic zoominginhibition signal to the camera microcomputer 208. Upon completion ofthe operation to be performed in one of the aforementioned steps 1310,1314 and 1315, control returns to the main routine in step 1316.

[0141] Next, the case of integrating the processing performed by thelens microcomputer 115 with the processing performed by the cameramicrocomputer 208 will be described.

[0142]FIG. 18 is a diagram illustrating the timing with which an outputvideo signal is changed from video signals of an optical zooming regionto those of an electronic zooming region when a zooming operation isperformed from the wide side to the tele side. In this diagram, thetransverse axis represents time. As viewed in this diagram, the righterthe position of a time point on the transverse axis becomes, the latertime the time point indicates. Reference numeral 1101 denotes a rowrepresenting a sequence of fields of a standard television signal.Fields (n−1) to (n+4) are shown in this figure. Reference numeral 1102designates a row showing various kinds of processing to be performed bythe camera microcomputer 208 in the respective fields. Theaforementioned kinds of processing illustrated in FIG. 7 are performedin the respective fields.

[0143] Reference numeral 1103 designates a row showing the field Nos. offields in which the input video signals 300 are obtained in the imager201 by photoelectric conversion. Incidentally, a field, in which a videosignal is read from the imager 201, is immediately subsequent to a fieldin which this video signal is obtained by photoelectric conversion.Thus, the field No. of this field is smaller than the field No. thereofshown in the row 1101 by 1. Reference numeral 1104 designates a rowshowing the field No. of a field in which an output signal of the adder307 is obtained in the imager 201 by photoelectric conversion. However,an output signal of the adder 307 is indefinite until a video signal isfetched in the memory circuit 301. After a video signal is fetchedthereto, a signal delayed by 1 field is outputted from the adder 307.

[0144] Reference numeral 1105 denotes a row indicating which of theinput video signal 300 and the output signal of the adder 307 isselected by the output switch circuit 309 according to a switch signaloutputted from the microcomputer interface circuit 304. Referencenumeral 1106 designates a row indicating the field No. of a field inwhich the output video signal 310 is obtained in the imager 201 byphotoelectric conversion.

[0145] Next, a process flow of the zooming processing will be describedby concentrating on the processing to be performed by the cameramicrocomputer 208.

[0146] In the zooming operation from the wide side to the tele side, thelens microcomputer 115 detects at the time t(n−1)1 that the currentfocal length f of the zoom lens group is not less than the focal lengthfn at which the zoom lens group would reach the tele end within({fraction (1/60)}) seconds if the zoom lens group moved by maintainingthe current zooming speed. Then, the lens microcomputer 115 prepareselectronic zooming permission information for the next communicationwith the camera microcomputer 208 in the field n if the optical zoomlens reaches the optical tele end at the time t(n)1.

[0147] In the field “P”, an electronic zooming enabling signal is sentfrom the lens microcomputer 115 to the camera microcomputer 208 by thecommunication performed at the time t(n)1. In the zooming processing atthe time t(n)2, the camera microcomputer 208 performs an operation forcausing the memory circuit 301 to store the input video signal 300 inthe time (n+1). In the field (n+1), an operation for causing the inputvideo signal 300 obtained in the field (n+3) to be stored in the memorycircuit 301 is performed. Moreover, if the optical zoom lens groupreaches the optical tele end at the time t(n)3, the lens microcomputer115 prepares electronic zooming permission information for the nextcommunication with the camera microcomputer 208.

[0148] In the field “n”, an electronic zooming preparation permissionsignal is sent from the lens microcomputer 115 to the cameramicrocomputer 208 by the communication performed at the time t(n+1)1. Inthe zooming processing at the time t(n+1)2, the camera microcomputer 208performs an operation for causing the memory circuit 301 to store theinput video signal 300 in the time (n+1), and also performs operationsof enlarging an image, which is represented by the stored input videosignal 300 in the field (n+2), and of outputting a video signal (n+1)′representing an enlarged image to the output switch circuit 309, and ofselecting a received output of the adder 307 as an output of the outputswitch circuit 309.

[0149] In the field (n+2), an operation of storing the input videosignal 300, which is obtained in the field (n+3), in the memory circuit301 is performed during the zooming processing at the time t(n+2)1.Further, the circuit performs operations of enlarging an image, which isrepresented by the stored input video signal 300 in the field (n+2), inthe field (n+3), and of outputting a video signal (n+1)′ representing anenlarged image, and of selecting a received output of the adder 307 asan output of the output switch circuit 309. Further, the circuitperforms operations of enlarging an image, which is represented by thestored input video signal 300 in the field (n+3), in the field (n+4),and of outputting a video signal (n+1)′ to the output switch circuit309. In the field (n+3) and the subsequent fields, the same processingas performed in the field (n+2) is carried out.

[0150] Next, change 1106 in the output video signal 310 with time willbe described. Because the zoom lens reaches the optical tele end in thefield “n”, signals obtained in the imager 201 by photoelectricconversion in the fields up to (n−1) and signals obtained byphotoelectric conversion in the field “n”, in which the optical zoomingis ceased in the middle thereof, are video signals obtained during theoptical zooming. Thus, the output video signals outputted in the fieldsup to (n+1) are signals outputted during the optical zooming. Each ofthe output video signals 310 outputted in the field (n+2) and thesubsequent fields are obtained by enlarging the signal stored in thememory circuit 301 in the immediately precedent field and are videosignals obtained during the electronic zooming.

[0151] Incidentally, in the aforementioned third embodiment, the lensmicrocomputer 115 is adapted to detect that the current focal length fof the zoom lens group is not less than the focal length fn at which thezoom lens group would reach the tele end within ({fraction (1/60)})seconds if the zoom lens group moved by maintaining the current zoomingspeed. Further, the lens microcomputer 115 is adapted to prepareelectronic zooming permission information for the next communicationwith the camera microcomputer 208. However, even in the case that alarge time delay is caused in the timing of obtaining electronic zoomingpermission information from the lens microcomputer 115 by the cameramicrocomputer 208 for some reason after the zoom lens group reaches theoptical tele end, smooth switching between optical and electroniczooming operations is realized by setting fn, which meets theaforementioned inequality f≦fn where f is the focal length of the zoomlens group, in such a manner that the zoom lens group would reach theoptical tele end within a time period, which is an integral multiple ofthe cycle of the communication between the lens microcomputer 115 andthe camera microcomputer 208 corresponding to the aforementioned timedelay, if the zoom lens group moved by maintaining the current zoomingspeed.

[0152] As described above, according to the third embodiment, anelectronic zooming preparation permission signal and an electroniczooming enabling signal are outputted to the camera body unit during thezooming operation. Thus, even in the case that there is a delay inperforming electronic zooming, a zooming operation is smoothly performedwithout suspension.

[0153] Further, according to the third embodiment, electronic zooming isenabled when the aforementioned signals are inputted from the lens unit.Consequently, even in the case that a delay occurs in performingelectronic zooming, a zooming operation is smoothly performed withoutsuspension.

[0154] (Fourth Embodiment)

[0155] In the case that the interchangeable lens unit 100 as anelectrically-controllable optical zooming mechanism, similarly as in thecase of the first to third embodiment, optical zooming and electroniczooming are achieved under the control of the camera microcomputer 208.However, in the case that, as shown in FIGS. 16 and 17, the lens units130 and 140 have no electrically-controllable optical zoomingmechanisms, the control of electronic zooming is not taken intoconsideration.

[0156] This fourth embodiment is enabled to smoothly function anelectronic zooming mechanism of the camera body unit according to thetype of an external lens unit (for instance, an interchangeable lensunit), regardless of the presence/absence of an electricallycontrollable optical zooming mechanism in the external lens unit.

[0157] Hereinafter, the fourth embodiment will be described.

[0158] Video camera of the fourth embodiment has a camera body unitwhose hardware configuration is the same as that of the body unit 200shown in FIG. 4. This camera body unit 200 is combined with aninterchangeable lens unit that has the same hardware configuration asthat of the interchangeable lens unit shown in FIG. 19, 20 or 4.Incidentally, the fourth embodiment is different in software used in thecamera microcomputer 208 and the lens microcomputer 115 from theconventional video camera. Hereinafter, only the differencestherebetween will be described.

[0159] The flow of the processing to be performed by the cameramicrocomputer 208 is broadly similar to the flow illustrated in FIGS. 7and 8. FIG. 21 shows a process flow of step 406 of this embodiment,which is illustrated in FIG. 7.

[0160] In step S1401, the processing is started. Then, in step S1402,the camera microcomputer 208 checks whether the zoom keys 210 and 211 ofthe camera body unit 200 are not operated or whether each of these zoomkeys is operated in the tele or wide direction. If the zoom keys areoperated, control advances to step S1403. If not operated, controlproceeds to step S1414. In step S1403, the camera microcomputer 208checks manual zooming capability information sent from the lensmicrocomputer 115. If manual zooming is possible, control advances tostep S1414. Otherwise, control proceeds to step S1404 whereupon thecamera microcomputer 208 checks presence-of-zooming-unit informationsent from the lens microcomputer of the interchangeable lens unit. Ifthe lens unit has a zooming unit, control advances to step S1405.Otherwise, control unit proceeds to step S1410. In step S1405, thecamera microcomputer 208 checks whether the zoom keys 210 and 211 of thecamera body unit 200 are operated in a direction corresponding to thetele side. If the zoom keys are operated in a direction corresponding tothe tele side, control advances to step S1406. If the zoom keys areoperated in a direction corresponding to the wide side, control proceedsto step S1409. In step S1406, the camera microcomputer 208 checksoptical tele end information sent from the lens microcomputer of theinterchangeable lens unit. If this information indicates the opticaltele end, control advances to step S1407. Otherwise, control proceeds tostep S1413. In step S1407, the camera microcomputer 208 checks whetherthe zooming unit is at the tele end in the case of electronic zooming.If so, control advances to step S1414. Otherwise, control proceeds tostep S1408. In step S1414, the camera microcomputer 208 checks whetheran electronic zooming operation is currently being performed. If so,control advances to step S1408. Otherwise, control proceeds to stepS1415. In step S1408, an electronic zooming operation is performed byincreasing or decreasing the aforementioned interpolation coefficientsaccording to which of the switches 210 and 211 is pushed. Moreover, thecamera microcomputer 208 controls the enlargement processing circuit 205according to a result of the electronic zooming operation. Then, controladvances to step S1414.

[0161] On the other hand, in step S1410, the camera microcomputer 208checks whether each of the zoom keys 210 and 211 of the camera body unit200 is operated in a direction corresponding to the tele or widedirection. If operated in the direction corresponding to the tele side,control proceeds to, step S1411. Conversely, if operated in thedirection corresponding to the wide side, control advances to stepS1412. In step S1411, the camera microcomputer 208 checks whether thezooming unit is at the tele end in the case of electronic zooming. Ifso, control advances to step S1414. Otherwise, control proceeds to stepS1408. In step S1412, the camera microcomputer 208 checks whether anelectronic zooming operation is currently being performed. If so,control advances to step S1408. Otherwise, control proceeds to stepS1414.

[0162] In step S1413, the camera microcomputer 208 sets a control signalfor moving the zoom lens to the tele side. In step S1414, the cameramicrocomputer 208 sets a control signal for stopping the zoom lens. Instep S1415, the camera microcomputer 208 sets a control signal formoving the zoom lens to the wide side.

[0163] Upon completion of the operation performed in one of theaforementioned steps S1413, S1414 and S1415, control returns to anupper-level routine in step S1416.

[0164] Next, the video camera having the combination of the camera bodyunit 200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 130 of the hardware configuration shown inFIG. 19 will be first described below.

[0165] As shown in FIG. 19, reference numeral 130 designates aninterchangeable lens unit detachably attached to a camera body unit 200.In the interchangeable lens unit 130, reference numeral 131 denotes afocusing lens group for performing a focusing function; and 132 avariator lens group for changing a magnification, which consists of avariator lens and a compensator lens and changes the position thereof inaccordance with a cam (not shown) to thereby vary the focal lengththereof. Reference numeral 133 designates a fixed image-forming lensgroup. These lens groups 131 to 133 constitute a lens system of what iscalled a front lens focusing type.

[0166] Reference numeral 134 denotes a zoom ring for manually moving thevariator lens group 132 by a cameraman. A zooming operation is enabledonly by using this zoom ring 134 (an optical zooming mechanism whichdoes not operate according to a control signal inputted from an externaldevice). Reference numeral 135 designates a stepping motor for movingthe focusing lens group 131; 136 a zoom encoder; 137 a lensmicrocomputer which is operative to communicate with the microcomputer208 of the camera body unit 200 and to control the stepping motor 135.

[0167]FIG. 22 is a flowchart illustrating a part of processing to beperformed by the lens microcomputer 137.

[0168] In step S1501, the processing is started. Then, in step S1502,the lens microcomputer 137 sets presence-of-zooming-unit information andmakes preparations for sending this information to the cameramicrocomputer 208. Then, control advances to step S1503 whereupon thelens microcomputer 137 sets manual zooming capability information andmakes preparations for sending this information to the cameramicrocomputer 208. Subsequently, control proceeds to step S1504whereupon it is judged by interruption processing whether thecommunication between the lens microcomputer 137 and the cameramicrocomputer 208 is completed. If completed, control advances to stepS1505. Otherwise, control goes back to step S1504. In step S1505, thelens microcomputer 137 reads a value indicated by the zoom encoder 136.Then, control proceeds to step S1506 whereupon a driving amount of thefocusing lens is calculated from the value indicated by the zoom encoder136 and from an autofocusing estimation value provided by the camerabody unit 200 (incidentally, the detailed description of this value isomitted for simplicity of description). Subsequently, control advancesto step S1507 whereupon the stepping motor for moving the focusing lens131 is driven according to the driving amount of the focusing lenscalculated in step S1506. Thereafter, control goes back to step S1502.

[0169] As is understood from the foregoing description, in the case ofthe combination of the camera body unit 200 and the interchangeable lensunit 130, the manual zooming capability information (indicating thepresence of the optical zooming mechanism which does not operateaccording to control information provided from an external device) isset (in step S1503) by the lens microcomputer 137. Thus, the cameramicrocomputer 208 judges (in step S1403) that a manual zooming operationcan be performed. Consequently, an electronic zooming mechanism (theenlargement processing circuit 205) provided in the camera body unit 200does not function.

[0170] Next, the video camera having the combination of the camera bodyunit 200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 140 of the hardware configuration shown inFIG. 20 will be described below.

[0171] As shown in FIG. 20, reference numeral 140 designates aninterchangeable lens unit detachably attached to a camera body unit 200.In the interchangeable lens unit 140, reference numeral 141 denotes afocusing lens group constituting a short focus lens; and 142 a lensmicrocomputer which is operative to communicate with the microcomputer208 of the camera body unit 200.

[0172]FIG. 23 is a flowchart illustrating a part of processing to beperformed by the lens microcomputer 142.

[0173] In step S1601, the processing is started. Then, in step S1602,the lens microcomputer 142 clears presence-of-zooming-unit informationand makes preparations for sending absence-of-zooming-unit informationto the camera microcomputer 208. Then, control advances to step S1603whereupon the lens microcomputer 142 sets manual zooming capabilityinformation and makes preparations for sending information, whichindicates that manual zooming cannot be performed, to the cameramicrocomputer 208. Subsequently, control proceeds to step S1604whereupon it is judged by interruption processing whether thecommunication between the lens microcomputer 142 and the cameramicrocomputer 208 is completed. If completed, control goes back to stepS1602. Otherwise, control goes back to step S1604.

[0174] As is understood from the foregoing description, in the case ofthe combination of the camera body unit 200 and the interchangeable lensunit 140, the manual zooming capability information (indicating thepresence of the optical zooming mechanism) is cleared (in step S1602) bythe lens microcomputer 142. Further, the manual zooming capabilityinformation is cleared (in step S1603). Thus, the camera microcomputer208 judges (in steps S1403 and S1404) that a manual zooming operationcannot be performed and no zooming unit is provided in the camera.Consequently, an electronic zooming mechanism (the enlargementprocessing circuit 205) provided in the camera body unit 200 functions.

[0175] Next, the video camera having the combination of the camera bodyunit 200 of the hardware configuration and the interchangeable lens unit100 of the hardware configuration, which are shown in FIG. 4, will bedescribed below.

[0176]FIG. 24 is a flowchart illustrating processing concerning azooming operation, which is a part of the entire processing to beperformed by the lens microcomputer 115. In step S1701, the processingis started. Then, in step S1702, the lens microcomputer 115 checkswhether a zoom lens stop request signal (S1414) comes thereto from acamera microcomputer 208. If the zoom lens group has already stopped,control proceeds to step S1708. Otherwise, control advances to stepS1703 whereupon the lens microcomputer 115 checks according to theinformation sent by the camera microcomputer 208 which of the teledirection and the wide direction the moving direction of the zoom lensgroup is. If the moving direction of the zoom lens group is the teledirection, control proceeds to step S1704. If the wide direction,control advances to step S1705.

[0177] In step S1704, the lens microcomputer 115 checks whether the zoomlens group is positioned at the tele end. If so, control proceeds tostep S1708. Otherwise, control advances to step S1706. Further, in stepS1705, the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step S1708.Otherwise, control advances to step S1706. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step S1706. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in stepS1707. Furthermore, in step S1708, the zoom lens group is stopped.

[0178] Upon completion of the operation performed in step S1707 orS1708, the lens microcomputer 115 checks in step S1709 whether the zoomlens group is placed at the tele end. If so, control proceeds to stepS1710. Otherwise, control advances to step S1711. In step S1710, thelens microcomputer 115 sets optical tele end information and makespreparations for sending this information to the camera microcomputer208. Further, in step S1711, the lens microcomputer 115 clears opticaltele end information and makes preparations for sending information,which indicates that the zoom lens group is not placed at the tele end,to the camera microcomputer 208. In step S1712, the lens microcomputer115 sets presence-of-zooming-unit information and makes preparations forsending this information to the camera microcomputer 208. Then, controlproceeds to step S1713 whereupon the lens microcomputer 115 clearsmanual zooming capability information and makes preparations for sendinginformation, which indicates that manual zooming cannot be performed, tothe camera microcomputer 208. Subsequently, control advances to stepS1714. Further, control returns to a main routine in step S1714.

[0179] As is understood from the foregoing description, in the case ofthe combination of the camera body unit 200 and the interchangeable lensunit 100, the presence-of-zooming-unit information is set (in stepS1712) by the lens microcomputer 115. Further, the manual zoomingcapability information is cleared (in step S1713). Thus, the cameramicrocomputer 208 judges (in steps S1403 and S1404) that a manualzooming operation cannot be performed and a zooming unit is provided inthe camera. Consequently, an electronic zooming mechanism provided inthe camera body unit 200 functions.

[0180] (Fifth Embodiment)

[0181] A video camera of the fifth embodiment has a camera body unit ofthe same hardware configuration as the configuration of the unit 200illustrated in FIG. 4, similarly as the fourth embodiment does. In thecase of the fifth embodiment, such a camera body unit is combined withan interchangeable lens unit of the same hardware configuration as theconfiguration of the interchangeable lens unit shown in FIG. 19, 20 or4. Incidentally, the fifth embodiment is different in software used inthe camera microcomputer 208 and the lens microcomputer 115 from theconventional video camera and the fourth embodiment. Hereunder, only thedifferences therebetween will be described.

[0182] The flow of the processing to be performed by the cameramicrocomputer 208 of this embodiment is broadly similar to the flowillustrated in FIGS. 7 and 8. FIG. 25 shows a process flow of step 406of this embodiment, which is illustrated in FIG. 7.

[0183] In step S1801, the processing is started. Then, in step S1802,the camera microcomputer 208 checks whether the zoom keys 210 and 211 ofthe camera body unit 200 are not operated or whether each of these zoomkeys is operated in the tele or wide direction. If the zoom keys areoperated, control advances to step S1803. If not operated, controlproceeds to step S1814. In step S1803, the camera microcomputer 208checks specific lens group information sent from the lens microcomputerof the interchangeable lens unit. If the interchangeable lens unitbelongs to the specific lens group, control advances to step S1414.Otherwise, control proceeds to step S1804 whereupon the cameramicrocomputer 208 checks presence-of-zooming-unit information sent fromthe lens microcomputer of the interchangeable lens unit. If the lensunit has a zooming unit, control advances to step S1805. Otherwise,control unit proceeds to step S1810. In step S1805, the cameramicrocomputer 208 checks whether the zoom keys 210 and 211 of the camerabody unit 200 are operated in a direction corresponding to the teleside. If the zoom keys are operated in a direction corresponding to thetele side, control advances to step S1806. If the zoom keys are operatedin a direction corresponding to the wide side, control proceeds to stepS1809. In step S1806, the camera microcomputer 208 checks optical teleend information sent from the lens microcomputer of the interchangeablelens unit. If this information indicates the optical tele end, controladvances to step S1807. Otherwise, control proceeds to step S1813. Instep S1807, the camera microcomputer 208 checks whether the zooming unitis at the tele end in the case of electronic zooming. If so, controladvances to step S1814. Otherwise, control proceeds to step S1808. Instep S1809, the camera microcomputer 208 checks whether an electroniczooming operation is currently being performed. If so, control advancesto step S1808. Otherwise, control proceeds to step S1815. In step S1808,an electronic zooming operation is performed by increasing or decreasingthe aforementioned interpolation coefficients according to which of theswitches 210 and 211 is pushed. Moreover, the camera microcomputer 208controls the enlargement processing circuit 205 according to a result ofthe electronic zooming operation. Then, control advances to step S1814.

[0184] On the other hand, in step S1810, the camera microcomputer 208checks whether each of the zoom keys 210 and 211 of the camera body unit200 is operated in a direction corresponding to the tele or widedirection. If operated in the direction corresponding to the tele side,control proceeds to step S1811. Conversely, if operated in the directioncorresponding to the wide side, control advances to step S1812. In stepS1811, the camera microcomputer 208 checks whether the zooming unit isat the tele end in the case of electronic zooming. If so, controladvances to step S1814. Otherwise, control proceeds to step S1808. Instep S1812, the camera microcomputer 208 checks whether an electroniczooming operation is currently being performed. If so, control advancesto step S1808. Otherwise, control proceeds to step S1814.

[0185] In step S1813, the camera microcomputer 208 sets a control signalfor moving the zoom lens group to the tele side. In step S1814, thecamera microcomputer 208 sets a control signal for stopping the zoomlens. In step S1815, the camera microcomputer 208 sets a control signalfor moving the zoom lens to the wide side.

[0186] Upon completion of the operation performed in one of theaforementioned steps S1813, S1814 and S1815, control returns to anupper-level routine in step S1816.

[0187] Next, the video camera having the combination of the camera bodyunit 200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 130 of the hardware configuration shown inFIG. 19 will be first described below. It is assumed that theinterchangeable lens unit 130 has a manual zooming mechanism whichcannot be controlled by using a control signal inputted from an externaldevice, and that the lens unit 130 belongs to the “specific lens group”.

[0188]FIG. 26 is a flowchart illustrating a part of processing to beperformed by the lens microcomputer 137.

[0189] In step S1901, the processing is started. Then, in step S1902,the lens microcomputer 137 sets presence-of-zooming-unit information andmakes preparations for sending this information to the cameramicrocomputer 208. Then, control advances to step S1903 whereupon thelens microcomputer 137 sets specific lens group information and makespreparations for sending this information to the camera microcomputer208. Subsequently, control proceeds to step S1904 whereupon it is judgedby interruption processing whether the communication between the lensmicrocomputer 137 and the camera microcomputer 208 is completed. Ifcompleted, control advances to step S1905. Otherwise, control goes backto step S1904. In step S1905, the lens microcomputer 137 reads a valueindicated by the zoom encoder 136. Then, control proceeds to step S1906whereupon a driving amount of the focusing lens is calculated from thevalue indicated by the zoom encoder 136 and from an autofocusingestimation value provided by the camera body unit 200 (incidentally, thedetailed description of this value is omitted for simplicity ofdescription). Subsequently, control advances to step S1907 whereupon thestepping motor for moving the focusing lens 131 is driven according tothe driving amount of the focusing lens calculated in step S1906.Thereafter, control goes back to step S1902.

[0190] As is understood from the foregoing description, in the case ofthe combination of the camera body unit 200 and the interchangeable lensunit 130, the specific lens group information (indicating that the lensunit has an optical zooming mechanism which does not operate accordingto control information provided from an external device) is set (in stepS1903) by the lens microcomputer 137. Thus, the camera microcomputer 208judges (in step S1903) that the lens unit is a specific lens group.Consequently, an electronic zooming mechanism (the enlargementprocessing circuit 205) provided in the camera body unit 200 does notfunction.

[0191] Next, the video camera having the combination of the camera bodyunit 200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 140 of the hardware configuration shown inFIG. 20 will be described below. Incidentally, it is assumed that theinterchangeable lens unit 140 does not have a zooming mechanism and thusdoes not belong to the “specific lens group”.

[0192]FIG. 27 is a flowchart illustrating a part of processing to beperformed by the lens microcomputer 142.

[0193] In step S2001, the processing is started. Then, in step S2002,the lens microcomputer 142 clears presence-of-zooming-unit informationand makes preparations for sending absence-of-zooming-unit informationto the camera microcomputer 208. Then, control advances to step S2003whereupon the lens microcomputer 142 clears specific lens groupinformation and makes preparations for sending information, whichindicates that the lens unit does not belong to the specific lens group,to the camera microcomputer 208. Subsequently, control proceeds to stepS2004 whereupon it is judged by interruption processing whether thecommunication between the lens microcomputer 142 and the cameramicrocomputer 208 is completed. If completed, control goes back to stepS2002. Otherwise, control goes back to step S2004.

[0194] As is understood from the foregoing description, in the case ofthe combination of the camera body unit 200 and the interchangeable lensunit 140, the absence-of-zooming-unit information is set by the lensmicrocomputer 142. Further, the specific lens group information iscleared (in steps S2002 and S2003). Thus, the camera microcomputer 208judges (in steps S1803 and S1804) that the lens unit is not a specificlens group and no zooming unit is provided in the camera. Consequently,an electronic zooming mechanism (the enlargement processing circuit 205)provided in the camera body unit 200 functions.

[0195] Next, the video camera having the combination of the camera bodyunit 200 of the hardware configuration and the interchangeable lens unit100 of the hardware configuration, which are shown in FIG. 4, will bedescribed below. Incidentally, it is assumed that the interchangeablelens unit 100 does not have a manual zooming mechanism which cannot becontrolled by a control signal inputted from an external device and thatthe lens unit 100 does not the “specific lens group”.

[0196]FIG. 28 is a flowchart illustrating processing concerning azooming operation, which is a part of the entire processing to beperformed by the lens microcomputer 115. In step S2101, the processingis started. Then, in step S2102, the lens microcomputer 115 checkswhether the zoom lens stop request signal comes thereto from a cameramicrocomputer 208. If the zoom lens group has already stopped, controlproceeds to step S2108. Otherwise, control advances to step S2103whereupon the lens microcomputer 115 checks according to the informationsent by the camera microcomputer 208 which of the tele direction and thewide direction the moving direction of the zoom lens group is. If themoving direction of the zoom lens group is the tele direction, controlproceeds to step S2104. If the wide direction, control advances to stepS2105.

[0197] In step S2104, the lens microcomputer 115 checks whether the zoomlens group is positioned at the tele end. If so, control proceeds tostep S2108. Otherwise, control advances to step S2106. Further, in stepS2105, the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step S2108.Otherwise, control advances to step S2106. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step S2106. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in stepS2107. Furthermore, in step S2108, the zoom lens group is stopped.

[0198] Upon completion of the operation performed in step S2107 orS2108, the lens microcomputer 115 checks in step S2109 whether the zoomlens group is placed at the tele end. If so, control proceeds to stepS2110. Otherwise, control advances to step S2111. In step S2110, thelens microcomputer 115 sets optical tele end information and makespreparations for sending this information to the camera microcomputer208. Further, in step S2111, the lens microcomputer 115 clears opticaltele end information and makes preparations for sending information,which indicates that the zoom lens group is not placed at the tele end,to the camera microcomputer 208. In step S2112, the lens microcomputer115 sets presence-of-zooming-unit information and makes preparations forsending this information to the camera microcomputer 208. Then, controlproceeds to step S2113 whereupon the lens microcomputer 115 clearsspecific lens group information and makes preparations for sendinginformation, which indicates that the lens unit does not belong to thespecific lens group, to the camera microcomputer 208. Subsequently,control advances to step S2114. Further, control returns to a mainroutine in step S2114.

[0199] As is understood from the foregoing description, in the case ofthe combination of the camera body unit 200 and the interchangeable lensunit 100, the presence-of-zooming-unit information is set (in stepS2112) by the lens microcomputer 115. Further, the specific lens groupinformation is cleared (in step S2113). Thus, the camera microcomputer208 judges (in steps S1803 and S1804) that the lens unit is not aspecific lens group and a zooming unit is provided in the camera.Consequently, an electronic zooming mechanism provided in the camerabody unit 200 functions.

[0200] Incidentally, in the foregoing description of the fourth andfifth embodiments, it has been described that these embodiments areadapted to detect the zoom operating direction (namely, detect that thezoom lens group is operated toward the tele side or toward the wideside). However, the present invention is easily applied to a case thatthe camera has multi-zooming-speed in each zoom operating direction.

[0201] Further, even in the case that the camera body unit has aplurality of zoom operating means or that an external input device, suchas a remote control device, for a camera body unit has zoom lensoperating means, the present invention is easily applied to such a caseby handling these means as a single zoom operating means in the camerabody unit.

[0202] Moreover, in the foregoing description of the fifth embodiment,the specific lens group has been defined as a lens group having anoptical lens group that cannot be controlled by a control signalinputted from an external device. However, it is apparent that otherrequirements, such as performance, price and use of the interchangeablelens unit, may be employed as the requirements for the specific lensgroup. Any of such requirements may be applied to the processingperformed in the camera body unit, in view of consistency between such arequirement and the performance of or the manner of use of theelectronic zooming function.

[0203] As described above, according to the fourth and fifthembodiments, an electronic zooming mechanism of the camera body unitsmoothly functions according to the type of an external lens unit (forinstance, an interchangeable lens unit), regardless of thepresence/absence of an electrically controllable optical zoomingmechanism in the external lens unit.

[0204] As many apparently widely different embodiments of the presentinvention can be made without departing from the spirit and scopethereof, it is to be understood that the invention is not limited to thespecific embodiments thereof except as defined in the claims.

What is claimed is:
 1. A lens device comprising: variator lens means forperforming a zooming operation; zoom operating means for operating saidvariator lens means; information output means for outputting operationinformation sent from said zoom operating means and for outputtingzooming position information of said variator lens means; informationinput means for receiving control information, which is used forcontrolling said variator lens means, from an external device; andvariator control means for controlling a zooming operation of saidvariator lens means according to the inputted control information. 2.The lens device according to claim 1, wherein the control informationcontains information on at least one of a direction and a speed given tosaid variator lens means.
 3. The lens device according to claim 1,wherein said information output means outputs the operation informationwhen said variator lens means is placed at a tele end.
 4. An imagingapparatus comprising: imaging means for imaging an object and foroutputting an image signal; information input means for receivingexternal zoom operating information and zoom position information to besupplied to external variator lens means; zoom operating means forreceiving internal zoom operating information to be supplied to saidexternal variator lens means; and information output means forgenerating and outputting optical zooming control information to be usedfor controlling a zooming operation of said external variator lens meansaccording to the inputted external zoom operating information and theinputted zoom position information and the internal zoom operatinginformation received from said zoom operating means.
 5. The imagingapparatus according to claim 4, which further comprises: electroniczooming means for performing electronic enlargement processing on animage represented by the image signal; and electronic zooming controlmeans for controlling said electronic zooming means according to theinputted external zoom operating information, the inputted zoom positioninformation and the internal zoom operating information.
 6. The imagingapparatus according to claim 4, wherein the external zoom operatinginformation and the internal zoom operating information containinformation on at least one of a direction and a speed given to saidexternal variator lens means.
 7. The imaging apparatus according toclaim 5, wherein said electronic zooming means performs the enlargementprocessing when the zoom position information indicates a tele end. 8.The imaging apparatus according to claim 4, wherein said informationoutput means gives the external zoom operating information precedenceover the internal zoom operating information when the external zoomoperating information indicates that a zooming operation is beingperformed.
 9. The imaging apparatus according to claim 5, wherein saidelectronic zooming control means gives the external zoom operatinginformation precedence over the internal zoom operating information whenthe external zoom operating information indicates that a zoomingoperation is being performed.
 10. An imaging system comprising: a lensdevice having: a variator lens means for performing a zooming operation;lens-side zoom operating means for operating said variator lens means;lens-side information output means for outputting lens-side zoomoperating information and zoom position information on a zoom positionof said variator lens means, which are received from said lens-side zoomoperating means; lens-side information input means for receiving opticalzoom control information to be used for controlling said variator lensmeans; and variator control means for controlling a zooming operation ofsaid variator lens means according to the received control information,and an imaging apparatus having: imaging means for imaging an object andfor outputting an image signal; camera-body-side information input meansfor receiving the lens-side zoom operating information and zoom positioninformation from said lens-side information output means;camera-body-side zoom operating means for receiving camera-body-sidezoom operating information to be supplied to said variator lens means;and camera-body-side information output means for generating opticalzooming control information to be used to control a zooming operation ofsaid variator lens means, according to the received lens-side zoomoperating information and the received zoom position information and thecamera-body-side zoom operating information and for outputting theoptical zooming control information to said lens-side information inputmeans.
 11. The imaging system according to claim 10, wherein saidimaging apparatus further comprises: electronic zooming means forperforming electronic enlargement processing on an image represented bythe image signal; and electronic zooming control means for controllingsaid electronic zooming means according to the lens-side zoom operatinginformation, the zoom position information and the camera-body-side zoomoperating information.
 12. The imaging system according to claim 10,wherein the optical zooming control information contains information onat least one of a direction and a speed given to said variator lensmeans.
 13. The imaging system according to claim 10, wherein saidlens-side information output means outputs the lens-side zoom operatinginformation when said variator lens means is placed at a tele end. 14.The imaging system according to claim 11, wherein said electroniczooming control means performs the enlargement processing when the zoomposition information indicates a tele end.
 15. The imaging systemaccording to claim 10, wherein said camera-body-side information outputmeans gives the lens-side zoom operating information precedence over thecamera-body-side zoom operating information when the lens-side zoomoperating information indicates that a zooming operation is beingperformed.
 16. The imaging system according to claim 11, wherein saidelectronic zooming control means gives the lens-side zoom operatinginformation precedence over the camera-body-side zoom operatinginformation when the lens-side zoom operating information indicates thata zooming operation is being performed.
 17. The imaging system accordingto claim 10, wherein a cycle of transmission and reception ofinformation between said lens-side information output means and saidcamera-body-side information input means and between said lens-sideinformation input means and said camera-body-side information outputmeans is nearly equal to a cycle of a standard television verticalsynchronization signal.
 18. A computer readable storage medium forstoring a program causing a computer to execute the steps of: outputtingoperation information, which is obtained when a variator lens isoperated, and zoom position information which represents a zoom positionof said variator lens; inputting control information, which is used forcontrolling said variator lens, from an external device; and controllingsaid variator lens according to the inputted control information.
 19. Acomputer readable storage medium for storing a program causing acomputer to execute the steps of: imaging an object and outputting animage signal; receiving external zoom operating information and zoomposition information to be supplied to an external variator lens;receiving internal zoom operating information to be supplied to saidexternal variator lens; and generating and outputting optical zoomingcontrol information to be used for controlling a zooming operation ofsaid external variator lens according to the inputted external zoomoperating information and the inputted zoom position information and theinternal zoom operating information.
 20. A lens device comprising:variator lens means for performing a zooming operation; zoom operatingmeans for operating said variator lens means; information output meansfor outputting first zoom operating information, which is received fromsaid zoom operating means, and zoom position information representing azoom position of said variator lens means; information input means forreceiving second zoom operating information and zooming inhibitioninformation from an external device; and variator control means forcontrolling a zooming operation of said variator lens means according tothe first zoom operating information, the inputted second zoom operatinginformation and the inputted zooming inhibition information.
 21. Thelens device according to claim 20, wherein the first zoom operatinginformation and the second zoom operating information containinformation on at least one of a direction and a speed given to saidvariator lens means.
 22. The lens device according to claim 20, whereinsaid information output means outputs the first zoom operatinginformation when said variator lens means is placed at a tele end. 23.The lens device according to claim 20, wherein said variator controlmeans gives the first zoom operating information precedence over thesecond zoom operating information when the first zoom operatinginformation indicates that a zooming operation is being performed.
 24. Acamera apparatus comprising: imaging means for imaging an object and foroutputting an image signal; information input means for receiving firstzoom operating information and zoom position information to be suppliedto external variator lens means; zoom operating means for receivingsecond zoom operating information to be supplied to said externalvariator lens means; information output means for outputting the secondzooming control information and optical zooming inhibition informationto be used for inhibiting a zooming operation of said external variatorlens means; electronic zooming means for performing electronicenlargement processing on an image represented by the image signal; andelectronic zooming control means for controlling said electronic zoomingmeans according to the first zoom operating information, the zoomposition information and the second zoom operating information.
 25. Thecamera apparatus according to claim 24, wherein the first zoom operatinginformation and the second zoom operating information containinformation on at least one of a direction and a speed given to saidexternal variator lens means.
 26. The camera apparatus according toclaim 24, wherein said electronic zooming means performs the enlargementprocessing and said information output means outputs the optical zoominginhibition information when the first zoom operating information and thesecond zoom operating information indicate a tele end.
 27. The cameraapparatus according to claim 24, wherein said electronic zooming controlmeans and said information output means give the first zoom operatinginformation precedence over the second zoom operating information whenthe first zoom operating information indicates that a zooming operationis being performed.
 28. A camera system comprising: a lens devicehaving: a variator lens means for performing a zooming operation;lens-side zoom operating means for operating said variator lens means;lens-side information output means for outputting first zoom operatinginformation, which is received from said lens-side zoom operating means,and zoom position information on a zoom position of said variator lensmeans; lens-side information input means for receiving second zoomoperating information and zooming inhibition information from anexternal device; and variator control means for controlling a zoomingoperation of said variator lens means according to the received secondzoom operating information and the zooming inhibition information andthe first zoom operating information, and an imaging apparatus having:imaging means for imaging an object and for outputting an image signal;camera-body-side information input means for receiving the first zoomoperating information and zoom position information from said lens-sideinformation output means; camera-body-side zoom operating means forreceiving the second zoom operating information to be supplied to saidvariator lens means; and camera-body-side information output means foroutputting said lens-side information input means the second zoomoperating information and the optical zooming inhibition which is usedfor inhibiting said variator lens means from performing a zoomingoperation; electronic zooming means for performing electronicenlargement processing on an image represented by the image signal; andelectronic zooming control means for controlling said electronic zoomingmeans according to the first zoom operating information, the zoomposition information and the second zoom operating information.
 29. Thecamera system according to claim 28, wherein the first zoom operatinginformation and the second zoom operating information containinformation on at least one of a direction and a speed given to saidexternal variator lens means.
 30. The camera system according to claim28, wherein said lens-side information output means outputs the firstzoom operating information said electronic zooming control meansperforms the enlargement processing when said variator lens means isplaced at a tele end.
 31. The camera system according to claim 28,wherein said camera-body-side information output means and saidelectronic zooming means give the first zoom operating informationprecedence over the second zoom operating information when the firstzoom operating information indicates that a zooming operation is beingperformed.
 32. The camera system according to claim 28, wherein a cycleof transmission and reception of information between said lens-sideinformation output means and said camera-body-side information inputmeans and between said lens-side information input means and saidcamera-body-side information output means is nearly equal to a cycle ofa standard television vertical synchronization signal.
 33. A computerreadable storage medium for storing a program causing a computer toexecute the steps of: outputting first zoom operating information, whichis obtained when a variator lens is operated, and zoom positioninformation which represents a zoom position of said variator lens;inputting second zoom operating information and zooming inhibitioninformation, which are received from an external device; and controllingsaid variator lens according to the inputted second zoom operatinginformation, the inputted zooming inhibition information and the firstzoom operating information.
 34. A computer readable storage medium forstoring a program causing a computer to execute the steps of: imaging anobject and outputting an image signal; receiving first zoom operatinginformation and zoom position information to be supplied to an externalvariator lens; receiving second zoom operating information to besupplied to said external variator lens; outputting the second zoomingcontrol information and optical zooming inhibition information to beused for inhibiting said external variator lens from performing azooming operation; and performing electronic zooming for electronicallyenlarging an image represented by the image signal according to thefirst zoom operating information and the second zoom operatinginformation and the zoom position information.
 35. A lens control systemcomprising: a first device having optical variator means for opticallychanging a magnification of an image; a second device having electronicvariator means for electronically enlarging an image by signalprocessing; and first and second variator operating members respectivelyprovided in said first and second devices, wherein, when said opticalvariator means is operated, said optical variator means is controlled insaid first device according to information for operating said first andsecond variator operating members, wherein, when said electronicvariator means is operated, said electronic variator means is controlledin said second device according to information for operating said firstand second variator operating members, and wherein, during saidelectronic variator means is operated, said first device inhibits saidoptical variator means from operating.
 36. A camera system comprising: alens device having an optical variator lens for optically changing amagnification of an image; a camera device having electronic variatormeans for electronically enlarging an image by signal processing; alens-device-side variator operating member; and a camera-device-sidevariator operating member, wherein, when said optical variator lens isoperated, said optical variator lens is controlled in said lens deviceaccording to information for operating said lens-device-side andcamera-device-side variator operating members, wherein, when saidelectronic variator means is operated, said electronic variator means iscontrolled in said camera device according to information for operatingsaid lens-device-side and camera-device-side variator operating members,and wherein, during said electronic variator means is operated, a signalcausing said lens device to inhibit said optical variator lens fromoperating is transmitted to said lens device.
 37. A camera device foruse in a camera system having a lens device having an optical variatorlens for optically changing a magnification of an image, alens-device-side variator operating member and a camera-device-sidevariator operating member, said camera device comprising: electronicvariator means for electronically enlarging an image by signalprocessing, wherein, when said optical variator lens is operated, saidoptical variator lens is controlled in said lens device according toinformation for operating said lens-device-side and camera-device-sidevariator operating members, wherein, when said electronic variator meansis operated, said electronic variator means is controlled in said cameradevice according to information for operating said lens-device-side andcamera-device-side variator operating members, and wherein, during saidelectronic variator means is operated, a signal causing said lens deviceto inhibit said optical variator lens from operating is transmitted tosaid lens device.
 38. A camera device for use in a camera system havinga camera device having electronic variator means for electronicallyenlarging an image by signal processing, a lens-device-side variatoroperating member, and a camera-device-side variator operating member,said a lens device comprising: an optical variator lens for opticallychanging a magnification of an image, wherein, when said opticalvariator lens is operated, said optical variator lens is controlled insaid lens device according to information for operating saidlens-device-side and camera-device-side variator operating members,wherein, when said electronic variator means is operated, saidelectronic variator means is controlled in said camera device accordingto information for operating said lens-device-side andcamera-device-side variator operating members, and wherein, during saidelectronic variator means is operated, a signal causing said lens deviceto inhibit said optical variator lens from operating is transmitted tosaid lens device.
 39. A lens device comprising: variator lens means forperforming a zooming operation; control means for controlling thezooming operation of said variator lens means; and signal output meansfor outputting an electronic zooming enabling signal and an electroniczooming preparation signal for giving advance notice of the electriczooming enabling signal, during the zooming operation.
 40. The lensdevice according to claim 39, wherein said signal output means outputsthe electronic zooming enabling signal when said variator lens means isplaced at a tele end.
 41. The lens device according to claim 39, whereinsaid signal output means outputs the electronic zooming preparationsignal when said variator lens means reaches the tele end within apredetermined time if said variator lens means continues performing acurrent zooming operation.
 42. The lens device according to claim 39,wherein said signal output means outputs the electronic zoomingpreparation signal when said variator lens means reaches the tele endwithin a predetermined time, which is a predetermined integral multipleof a cycle of a standard television signal, if said variator lens meanscontinues performing a current zooming operation.
 43. An imagingapparatus comprising: imaging means for imaging an object and foroutputting an image signal; electronic zooming means for electronicallyenlarging an image represented by the image signal; signal input meansfor receiving an electronic zooming preparation permission signal and anelectronic zooming enabling signal; and control means for enablingcontrol of said electronic zooming means when each of the electroniczooming preparation permission signal and the electronic zoomingenabling signal is received.
 44. The imaging apparatus according toclaim 43, wherein said signal input means receives position informationof a zoom lens.
 45. The imaging apparatus according to claim 43, whereinsaid control means starts controlling said electronic zooming means whenthe electronic zooming preparation permission signal is received.
 46. Animaging system comprising: a lens device having: a variator lens meansfor performing a zooming operation; first control means for controllingthe zooming operation of said variator lens means; and signal outputmeans for outputting an electronic zooming enabling signal and anelectronic zooming preparation permission signal which gives advancenotice of the electric zooming enabling signal, during the zoomingoperation, and an imaging apparatus having: imaging means for imaging anobject and for outputting an image signal; electronic zooming means forperforming electronic enlargement processing on an image represented bythe image signal; signal input means for receiving an electronic zoomingpreparation permission signal and an electronic zooming enabling signal;and second control means for enabling control of said electronic zoomingmeans when each of the electronic zooming preparation permission signaland the electronic zooming enabling signal is received.
 47. The imagingsystem according to claim 46, wherein said signal output means outputsthe electronic zooming enabling signal when said variator lens means isplaced at a tele end.
 48. The imaging system according to claim 46,wherein, during said variator lens means performs the zooming operation,said signal output means outputs the electronic zooming preparationsignal if said variator lens means reaches the tele end within apredetermined time when said variator lens means continues performingthe zooming operation.
 49. The imaging system according to claim 46,wherein said signal output means outputs the electronic zoomingpreparation signal when said variator lens means reaches the tele endwithin a predetermined time, which is a predetermined integral multipleof a cycle of a standard television signal, if said variator lens meanscontinues performing a current zooming operation.
 50. The imaging systemaccording to claim 46, wherein said second control means startscontrolling said electronic zooming means when the electronic zoomingpreparation permission signal is received.
 51. The imaging systemaccording to claim 46, wherein said signal output means and said signalinput means transmit and receive the electronic zooming preparationpermission signal and the electronic zooming enabling signal insynchronization with a standard television vertical synchronizationsignal.
 52. A computer readable storage medium for storing a programcausing a computer to execute the steps of: controlling a zoomingoperation performed by a variator lens; and outputting an electroniczooming enabling signal and an electronic zooming preparation permissionsignal which gives advance notice of the electric zooming enablingsignal, during the zooming operation.
 53. A computer readable storagemedium for storing a program causing a computer to execute the steps of:imaging an object and outputting an image signal; performing electroniczooming for electronically enlarging an image represented by the imagesignal; receiving an electronic zooming preparation permission signaland an electronic zooming enabling signal; and enabling the electroniczooming when each of the electronic zooming preparation permissionsignal and the electronic zooming enabling signal is received.
 54. Animaging apparatus comprising: imaging means; electronic zooming meansfor enlarging an image taken by said imaging means; zoom input means forreceiving zoom operating information; lens information input means forreceiving first zoom information, which indicates presence or absence ofan optical zooming mechanism in an external lens means, and second zoominformation which indicates presence or absence of an optical zoomingmechanism, which does not operate in response to a control signalreceived from an external device, in said external lens means; controloutput means for outputting an optical zooming control signal whichinstructs said external lens means to perform a zooming operation; andcontrol means for controlling said optical zooming mechanism of saidexternal lens means through said electronic zooming means and said lenscontrol output means according to the zoom operating informationinputted to said zoom input means in such a manner as to be able to bedriven, in a case that the first zoom information indicates the presenceof said optical zooming mechanism and that the second zoom informationindicates the absence of said optical zooming mechanism, and forcontrolling said electronic zooming means in such a manner as to be Ableto be driven, in a case that the first zoom information indicates theabsence of said optical zooming mechanism, and for controlling saidelectronic zooming means in such a manner as not to be driven, in a casethat the second zoom information indicates the presence of said opticalzooming mechanism.
 55. The imaging apparatus according to claim 54,wherein, when said external lens means is included in a specific lensgroup containing a lens that causes the second zoom information toindicate the presence of said optical zooming mechanism, the secondzooming information on said external lens means is permitted to indicatethe presence of said optical zooming mechanism.
 56. The imagingapparatus according to claim 54, wherein information represented by theoptical zooming control signal includes at least one kind of informationrepresenting a zooming direction to be given to said external lensmeans, information representing a zooming speed to be given thereto, andinformation representing both a zooming direction and a zooming speed tobe given thereto.
 57. An imaging apparatus comprising: imaging means;electronic zooming means for enlarging an image taken by said imagingmeans; zoom input means for receiving zoom operating information; lensinformation input means for receiving zoom information, which indicatespresence or absence of an optical zooming mechanism in an external lensmeans, and specific lens group information which indicates whether saidexternal lens means belongs to a specific lens group; control outputmeans for outputting an optical zooming control signal which instructssaid external lens means to perform a zooming operation; and controlmeans for controlling said optical zooming mechanism of said externallens means through said electronic zooming means and said lens controloutput means according to the zoom operating information inputted tosaid zoom input means in such a manner as to be able to be driven, in acase where the zoom information indicates the presence of said opticalzooming mechanism and where the specific lens group informationindicates that said external lens means does not belong to said specificlens group, and for controlling said electronic zooming means in such amanner as to be able to be driven, in a case where the zoom informationindicates the absence of said optical zooming mechanism, and forcontrolling said electronic zooming means in such a manner as not to bedriven, in a case where the specific lens group information indicatesthat said external lens means belongs to said specific lens group. 58.The imaging apparatus according to claim 57, wherein, when said specificlens group contains a lens having an optical mechanism that does notoperate in response to a control signal received from an externaldevice.
 59. The imaging apparatus according to claim 57, whereininformation represented by the optical zooming control signal includesat least one kind of information representing a zooming direction to begiven to said external lens means, information representing a zoomingspeed to be given thereto, and information representing both a zoomingdirection and a zooming speed to be given thereto.